混凝土搅拌车搅拌总成建模与仿真

Properties of Fresh ConcreteEdited by H.-J. Wierig Fresh concrete is a mixture of water, cement, aggregate and admixture (if any). After mixing, operations such as transporting, placing, compacting and finishing of fresh concrete can all considerably affect the properties of hardened concrete. It is important that the constituent materials remain uniformly distributed within the concrete mass during the various stages of its handling and that full compaction is achieved. When either of these conditions is not satisfied the properties of the resulting hardened concrete, for example, strength and durability, are adversely affected.The characteristics of fresh concrete which affect full compaction are its consistency, mobility and compactability. In concrete practice these are often collectively known as workability. The ability of concrete to maintain its uniformity is governed by its stability, which depends on its consistency and its cohesiveness. Since the methods employed for conveying, placing and consolidatingd a concrete mix, as well as the nature of the section to be cast, may vary from job to job it follows that the corresponding workability and stability requirements will also vary. The assessment of the suitability of a fresh concrete for a particular job will always to some extent remain a matter of personal judgment.In spite of its importance, the behaviour of plastic concrete often tends to be overlooked. It is recommended that students should learn to appreciate the significance of the various characteristics of concrete in its plastic state and know how these may alter during operations involved in casting a concrete structure.13.1 WorkabilityWorkability of concrete has never been precisely defined. For practical purposes it generally implies the ease with which a concrete mix can be handled from the mixer to its finally compacted shape. The three main characteristics of the property are consistency, mobility and compactability. Consistency is a measure of wetness or fluidity. Mobility defines the ease with which a mix can flow into and completely fill the formwork or mould. Compactability is the ease with which a given mix can be fully compacted, all the trapped air being removed. In this context the required workability of a mix depends not only on the characteristics and relative proportions of the constituent materials but also on (1) the methods employed for conveyance and compaction, (2) the size, shape and surface roughness of formwork or moulds and (3) the quantity and spacing of reinforcement.Another commonly accepted definition of workability is related to the amount of useful internal work necessary to produce full compaction. It should be appreciated that the necessary work again depends on the nature of the section being cast. Measurement of internal work presents many difficulties and several methods have been developed for this purpose but none gives an absolute measure of workability.The tests commonly used for measuring workability do not measure the individual characteristics (consistency, mobility and compactability) of workability. However, they do provide useful and practical guidance on the workability of a mix. Workability affects the quality of concrete and has a direct bearing on cost so that, for example, anunworkable concrete mix requires more time and labour for full compaction. It is most important that a realistic assessment is made of the workability required for given site conditions before any decision is taken regarding suitable concrete mix proportions.13.2 Measurement of WorkabilityThree tests widely used for measuring workability are the slump, compacting factor and V-B consistometer tests (figure 13.1). These are standard tests in the United Kingdom and are described in detail in BS 1881: Part 2. Their use is also recommended in CP 110: Part 1. It is important to note that there is no single relationship between the slump, compacting factor and V-B results for different concretes. In the following sections the salient features of these tests together with their merits and limitations are discussed.Slump TestThis test was developed by Chapman in the United States in 1913. A 300 mm high concrete cone, prepared under standard conditions (BS 1881: Part 2) is allowed to subside and the slump or reduction in height of the cone is taken to be a measure of workability. The apparatus is inexpensive, portable and robustd and is the simplest of all the methods employed for measuring workability. It is not surprising that, in spite of its several limitations, the slump test has retained its popularity.Figure 13.1 Apparatus for workability measurement: (a) slump cone, (b) compacting factor and (c)V-B consistometerThe test primarily measures the consistency of plastic concrete and although it is difficult to see any significant relationship between slump and workability as defined previously, it is suitable for detecting changes in workability. For example, an increase in the water content or deficiency in the proportion of fine aggregate results in anincrease in slump. Although the test is suitable for quality-control purposes it should be remembered that it is generally considered to be unsuitable for mix design since concretes requiring varying amounts of work for compaction can have similar numerical values of slump. The sensitivity and reliability of the test for detecting variation in mixes of different workabilities is largely dependent on its sensitivity to consistency. The test is not suitable for very dry or wet mixes. For very dry mixes, with zero or near-zero slump, moderate variations in workability do not result in measurable changes in slump. For wet mixes, complete collapse of the concrete produces unreliable values of slump.Figure 13.2 Three main types of slumpThe three types of slump usually observed are true slump, shear slump and collapse slump, as illustrated in figure 13.2. A true slump is observed with cohesive and rich mixes for which the slump is generally sensitive to variations in workability. A collapse slump is usually associated with very wet mixes and is generally indicative of poor quality concrete and most frequently results from segregation of its constituent materials. Shear slump occurs more often in leaner mixes than in rich ones and indicates a lack of cohesion which is generally associated with harsh mixes (low mortar content). whenever a shear slump is obtained the test should be repeated and, ifpersistent, this fact should be recorded together with test results, because widely different values of slump can be obtained depending on whether the slump is of true or shear form.The standard slump apparatus is only suitable for concretes in which the maximum aggregate size does not exceed 37.5 mm. It should be noted that the value of slump changes with time after mixing owing to normal hydration processes and evaporation of some of the free water, and it is desirable therefore that tests are performed within a fixed period of time.Compacting Factor TestThis test, developed in the United Kingdom by Glanville et al. (1947), measures the degree of compaction for a standard amount of work and thus offers a direct and reasonably reliable assessment of the workability of concrete as previously defined. The apparatus is a relatively simple mechanical contrivance (figure 13.1) and is fully described in BS 1881: Part 2. The test requires measurement of the weights of the partially and fully compacted concrete and the ratio of the partially compacted weight to the fully compacted weight, which is always less than 1, is known as the compacting factor. For the normal range of concretes the compacting factor lies between 0.80 and 0.92. The test is particularly useful for drier mixes for which the slump test is not satisfactory. The sensitivity of the compacting factor is reduced outside the normal range of workability and is generally unsatisfactory for compacting factors greater than 0.92.It should also be appreciated that, strictly speaking, some of the basic assumptions of the test are not correct. The work done to overcome surface friction of the measuring cylinder probably varies with the characteristics of the mix. It has been shown by Cusens (1956) that for concretes with very low workability the actual work required to obtain full compaction depends on the richness of a mix while the compacting factor remains sensibly unaffected. Thus it follows that the generally held belief that concretes with the same compacting factor require the same amount of work for full compaction cannot always be justified. One further point to note is that the procedure for placing concrete in the measuring cylinder bears no resemblance to methods commonly employed on the site. As in the slump test, the measurement of compacting factor must be made within a certain specified period. The standard apparatus is suitable for concrete with a maximum aggregate size of up to 37.5 mm.V-B Consistometer TestThis test was developed in Sweden by B a hrner (1940) (see figure 13.1). Although generally regarded as a test primarily used in research its potential is now more widely acknowledged in industry and the test is gradually being accepted. In this test (BS 1881: Part 2) the time taken to transform, by means of vibration, a standard cone of concrete to a compacted flat cylindrical mass is recorded. This is known as the V-B time, in seconds, and is stated to the nearest 0.5 s. Unlike the two previous tests, the treatment of concrete in this test is comparable to the method of compacting concrete in practice. Moreover, the test is sensitive to change in consistency, mobility and compactability,and therefore a reasonable correlation between the test results and site assessment of workability can be expected.The test is suitable for a wide range of mixes and, unlike the slump and compacting factor tests, it is sensitive to variations in workability of very dry and also air-entrained concretes. It is also more sensitive to variation in aggregate characteristics such as shape and surface texture. The reproducibility of results is good. As for other tests its accuracy tends to decrease with increasing maximum size of aggregate; above 19.0 mm the test results become somewhat unreliable. For concretes requiring very little vibration for compaction the V-B time is only about 3 s. Such results are likely to be less reliable than for larger V-B times because of the difficulty in estimating the time of the end point (concrete in contact withd the whole of the underside of the plastic disc). At the other end of the workability range, such as with very dry mixes, the recorded V-B times are likely to be in excess of their true workability since prolonged vibration is required to remove the entrapped air bubbles under the transparent disc. To overcome this difficulty an automatic device which records the vertical settlement of the disc with respect to time can be attached to the apparatus. This recording device can also assist in eliminating human error in judging the end point. The apparatus for the V-B test is more expensive than that for the slump and compacting factor tests, requiring an electric power supply and greater experience in handling; all these factors make it more suitable for the precast concrete industry and ready-mixed concrete plants than for general site use.13.3 Factors Affecting WorkabilityVarious factors known to influence the workability of a freshly mixed concrete are shown in figure 13.3. From the following discussion it will be apparent that a change in workability associated with the constituent materials is mainly affected by water content and specific surface of cement and aggregate.Cement and WaterFigure 13.3 Factors affecting workability of fresh conreteTypical relationships between the cement-water ratio (by volume) and the volume fraction of cement for different workabilities are shown in figure 15.5. The change in workability for a given change in cement-water ratio is greater when the water content is changed than when only the cement content is changed. In general the effect of the cement content is greater for richer mixes. Hughes (1971) has shown that similar linear relationships exist irrespective of the properties of the constituent materials.For a given mix, the workability of the concrete decreases as the fineness of the cement increases as a result of the increased specific surface, this effect being more marked in rich mixtures. It should also be noted that the finer cements improve the cohesiveness of a mix. With the exception of gypsum, the composition of cement has no apparent effect on workability. Unstable gypsum is responsible for false set, which can impair workability unless prolonged mixing or remixing of the fresh concrete is carriedout. Variations in quality of water suitable for making concrete have no significant effect on workability.AdmixturesThe principal admixtures affecting improvement in the workability of concrete are water-reducing and air-entraining agents. The extent of the increase in workability is dependent on the type and amount of admixture used and the general characteristics of the fresh concrete.Workability admixtures are used to increase workability while the mix proportions are kept constant or to reduce the water content while maintaining constant workability. The former results in a slight reduction in concrete strength.Air-entraining agents are by far the most commonly used workability admixtures because they also improve both the cohesiveness of the plastic concrete and the frost resistance of the resulting hardened concrete. Two points of practical importance concerning air-entrained concrete are that for a given amount of entrained air, the increase in workability tends to be smaller for concretes containing rounded aggregates or low cement-water ratios (by volume) and, in general, the rate of increase in workability tends to decrease with increasing air content. However, as a guide it may be assumed that every 1 per cent increase in air content will increase the compacting factor by 0.01 and reduce the V-B time by 10 per cent.AggregateFor given cement, water and aggregate contents, the workability of concrete is mainly influenced by the total surface area of the aggregate. The surface area is governed by the maximum size, grading and shape of the aggregate. Workability decreases as the specific surface increases, since this requires a greater proportion of cement paste to wet the aggregate particles, thus leaving a smaller amount of paste for lubrication. It follows that, all other conditions being equal, the workability will be increased when the maximum size of aggregate increases, the aggregate particles become rounded or the overall grading becomes coarser. However, the magnitude of this change in workability depends on the mix proportions, the effect of the aggregate being negligible for very rich mixes (aggregate-cement ratios approaching 2). The practical significance of this is that for a given workability and cement-water ratio the amount of aggregate which can be used in a mix varies depending on the shape, maximum size and grading of the aggregate, as shown in figure 13.4 and tables 13.1 and 13.2. The influence of air-entrainment (4.5 per cent) on workability is shown also in figure 13.4.TABLE 13.1Effect of maximum size of aggregate of similar grading zone on aggregate-cement ratio of concrete having water-cement ratio of 0.55 by weight, based on McIntosh (1964)Maximum aggregatesize(mm)Aggregate-cement ratio (by weight)Low workability Medium workability High workability IrregulargravelCrushed rockIrregulargravelCrushed rockIrregulargravelCrushed rock9.5 5.3 4.8 4.7 4.2 4.4 3.719.0 37.56.27.65.56.45.46.54.75.54.95.94.45.2TABLE 13.2Effect of aggregate grading (maximum size 19.0 mm) on aggregate-cement ratio ofconcrete having medium workability and water-cement ratio of 0.55 by weight, based onMcIntosh (1964)Type of aggregateAggregate-cement ratioCoarse grading Fine gradingRounded gravel Irregular gravel Crushed rock 7.35.54.76.35.14.3Figure 13.4 Effect of aggregate shape on aggregate-cement ratio of concretes for different workabilities, based on Cornelius (1970)Several methods have been developed for evaluating the shape of aggregate, asubject discussed in chapter 12. Angularity factors together with grading modulus and equivalent mean diameter provide a means of considering the respective effects of shape, size and grading of aggregate (see chapter 15). Since the strength of a fully compacted concrete, for given materials and cement-water ratio, is not dependent on the ratio of coarse to fine aggregate, maximum economy can be obtained by using the coarse aggregate content producing the maximum workability for a given cement content (Hughes, 1960) (see figure 13.5). The use of optimum coarse aggregate content in concrete mix design is described in chapter 15. It should be noted that it is the volume fraction of an aggregate, rather than its weight, which is important.Figure 13.5 A typical relationship between workability and coarse aggregate content of concrete, based on Hughes (1960)The effect of surface texture on workability is shown in figure 13.6. It can be seen that aggregates with a smooth texture result in higher workabilities than aggregates with a rough texture. Absorption characteristics of aggregate also affect workability where dry or partially dry aggregates are used. In such a case workability drops, the extent of the reduction being dependent on the aggregate content and its absorption capacity.Ambient ConditionsEnvironmental factors that may cause a reduction in workability are temperature, humidity and wind velocityd. For a given concrete, changes in workability are governed by the rate of hydration of the cement and the rate of evaporation of water. Therefore both the time interval from the commencement of mixing to compaction and the conditions of exposure influence the reduction in workability. An increase in the temperature speeds up the rate at which water is used for hydration as well as its loss through evaporation. Likewise wind velocity and humidity influence the workability as they affect the rate of evaporation. It is worth remembering that in practice these factors depend on weather conditions and cannot be controlled.Figure 13.6 Effect of aggregate surface texture on aggregate-cement ratio of concretes for different workabilities, based on Cornelius (1970)TimeThe time that elapses between mixing of concrete and its final compaction depends onthe general conditions of work such as the distance between the mixer and the point of placing, site procedures and general management. The associated reduction in workability is a direct result of loss of free water with time through evaporation, aggregate absorption and initial hydration of the cement. The rate of loss of workability is affected by certain characteristics of the constituent materials, for example, hydration and heat development characteristics of the cement, initial moisture content and porosity of the aggregate, as well as the ambient conditions.For a given concrete and set of ambient conditions, the rate of loss of workability with time depends on the conditions of handling. Where concrete remains undisturbed after mixing until it is placed, the loss of workability during the first hour can be substantial, the rate of loss of workability decreasing with time as illustrated by curve A in figure 13.7. On the other hand, if it is continuously agitated, as in the case of ready-mixed concrete, the loss of workability is reduced, particularly during the first hour or so (see curve B in figure 13.7). However, prolonged agitation during transportation may increase the fineness of the solid particles through abrasion and produce a further reduction in workability. For concretes continuously agitated and undisturbed during transportation, the time intervals permitted (BS 1926) between the commencement of mixing and delivery on site are 2 hours and 1 hour respectively.For practical purposes, loss of workability assumes importance when concrete becomes so unworkable that it cannot be effectively compacted, with the result that its strength and other properties become adversely affected. Corrective measures frequently taken to ensure that concrete at the time of placing has the desired workability are eitheran initial increase in the water content or an increase in the water content with further mixing shortly before the concrete is discharged. When this results in a water content greater than that originally intended, some reduction in strength and durability of the hardened concrete is to be expected unless the cement content is increased accordingly. This important fact is frequently overlooked on site. It should be recalled that the loss of workability varies with the mix, the ambient conditions, the handling conditions and the delivery time. No restriction on delivery time is given in CP 110: Part 1 but the concrete must be capable of being placed and effectively compacted without the addition of further water. For detailed information on the use of ready-mixed concrete the reader is advised to consult the work of Dewar (1973).Figure 13.7 Loss of workability of concrete with time: (A) no agitation and (B)continuously agitated after mixing13.4 StabilityApart from being sufficiently workable, fresh concrete should have a composition such that its constituent materials remain uniformly distributed in the concrete during both the period between mixing and compaction and the period following compaction beforethe concrete stiffens. Because of differences in the particle size and specific gravities of the constituent materials there exists a natural tendency for them to separate. Concrete capable of maintaining the required uniformity is said to be stable and most cohesive mixes belong to this category. For an unstable mix the extent to which the constituent materials will separate depends on the methods of transportation, placing and compaction. The two most common features of an unstable concrete are segregation and bleeding.SegregationWhen there is a significant tendency for the large and fine particles in a mix to become separated, segregation is said to have occurred. In general, the less cohesive the mix the greater the tendency for segregation to occur. Segregation is governed by the total specific surface of the solid particles including cement and the quantity of mortar in the mix. Harsh, extremely wet and dry mixes as well as those deficient in sand, particularly the finer particles, are prone to segregation. As far as possible, conditions conducive to segregation such as jolting of concrete during transportation, dropping from excessive heights during placing and over-vibration during compaction should be avoided.Blemishes, sand streaks, porous layers and honeycombing are a direct result of segregation. These features are not only unsightly but also adversely affect strength, durability and other properties of the hardened concrete. It is important to realize that the effects of segregation may not be indicated by the routine strength tests on control specimens since the conditions of placing and compaction of the specimens differ fromthose in the actual structure. There are no specific rules for suspecting possible segregation but after some experience of mixing and handling concrete it is not difficult to recognize mixes where this is likely to occur. For example, if a handful of concrete is squeezed in the hand and then released so that it lies in the palm, a cohesive concrete will be seen to retain its shape. A concrete which does not retain its shape under these conditions may well be prone to segregation and this is particularly so far wet mixes.BleedingDuring compaction and until the cement paste has hardened there is a natural tendency for the solid particles, depending on size and specific gravity, to exhibit a downward movement. Where the consistency of a mix is such that it is unable to hold all its water some of it is gradually displaced and rises to the surface, and some may also leak through the joints of the formwork. Separation of water from a mix in this manner is known as bleeding. While some of the water reaches the top surface some may become trapped under the larger particles and under the reinforcing bars. The resulting variations in the effective water content within a concrete mass produce corresponding changes in its properties. For example, the strength of the concrete immediately underneath the reinforcing bars and coarse aggregate particles may be much less than the average strength and the resistance to percolation of water in these areas is reduced. In general, the concrete strength tends to increase with depth below the top surface. The water which reaches the top surface presents the most serious practical problems. If it is not removed, the concrete at and near the top surface will be much weaker andless durable than the remainder of the concrete. This can be particularly troublesome in slabs which have a large surface area. On the other hand, removal of the surface water will unduly delay the finishing operation on the site.The risk of bleeding increases when concrete is compacted by vibration although this may be minimized by using a correctly designed mix and ensuring that the concrete is not over-vibrated. Rich mixes tend to bleed less than lean mixes. The type of cement employed is also important, the tendency for bleeding to occur decreasing as the fineness of the cement or its alkaline and tricalcium aluminate (C3A) content increases. Air-entrainment provides another very effective means of controlling bleeding in, for example, wet lean mixes where both segregation and bleeding are frequently troublesome.。

第一作者：郑招强，男，1980年
生，工程师,从事专用汽车设计工
作。

图1 速度云图
图2 流线图
图3 搅拌初期运动⽮量图图4 搅拌稳定状态运动⽮量图图5 物料分布状态图
搅拌性能分析
罐体的搅拌性能体现在物料上就是物料的匀质性。

由于罐体的旋转使各物料颗粒的运动方向和速度均不相同，相互之间
[3]
产生剪切滑移以致相互穿插、扩散，从而使物料均匀混合为直观地观察不同部位物料的运动情况，在罐体轴线方向上，从罐口端至封头端，依次选取不同部位的物料，并分别用不同颜色标示，如图6所示。

经过一段时间的搅拌，从图7可以
图6 罐体不同位置物料图
图7 罐体不同位物料轴向运动轨迹图
图8 罐⼝侧物料圆周⽅向运动轨迹
图9 封头侧物料圆周⽅向运动轨迹
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96 建设机械技术与管理 2023.03 0 引 言泵车作为一种连续的混凝土输送机械，在施工中具有重要的作用。

泵车搅拌系统位于料斗内，主要用于对料斗内的水泥混凝土进行再次搅拌，防止混凝土泌水离析和塌落度损失，保持其可泵性和施工和易性。

搅拌系统设计得合理与否将直接影响泵车的泵送性能，比较理想的搅拌轴转速应有一定变化范围，在大方量泵送时搅拌速度应稍快，最高转速以30r/min 左右为宜，转速不能太低，否则易使骨料沉降，造成混凝土的离析[1]。

当正常工作中的叶片突然被卡时，驱动搅拌轴的液压马达进油腔压力会急剧升高，升高至系统限定值时，电磁换向阀换位，搅拌马达反转，起到预防和排除卡死的作用[2]。

为了提高泵车液压系统的自动化程度，确保设备的安全，料斗搅拌系统都应设置自动正反转油路[3]。

1 搅拌系统结构及工作原理泵车搅拌系统由搅拌马达，搅拌轴、左搅拌叶片、右搅拌叶片、轴承及其密封件等组成，工作时由液压马达直接驱动搅拌轴带动搅拌叶片搅拌[4]。

其液压工作原理图见图1。

其工作原理为液压泵在电机的驱动下工作，电磁换向阀3处于右位，在液压油的作用下搅拌马达4正转。

当搅拌系统压力升高至设定值以上，电气控制系统控制电磁换向阀电磁铁得电，电磁换向阀3处于左位，搅拌马达4反转。

如果系统压力继续升高至溢流阀设定压力，溢流阀开启卸荷。

2 搭建仿真模型通过搅拌系统液压工作原理图，使用AMESim 软件可以搭建搅拌系统的仿真模型，搭建好的仿真模型见图2。

泵的转速为100rev/min ，排量20cc/rev ；溢流阀设定压力15Mp ，粘性摩擦系数3Nm/（rev/min ）,马达转速为28rev/min ，电磁换向阀额定工作电流40mA ，电磁换向阀的换向使用线性的分段信号进行模拟。

基于AMESim 仿真的泵车搅拌系统研究Research on Mixing System of Pump Truck Based on AMESim周智勇（山西工程科技职业大学智能制造学院，山西 太原 030619）摘要：通过研究电磁换向阀、液压马达和溢流阀等液压元件的压力、流量变化情况，对泵车搅拌系统的工作特性展开了仿真研究。

液~液压力2005(8)2结论(l >在放大器的放大区内,改变给定电压!g 就可改变泵的流量输出静态工作点,调节灵活方便(2>系统设计时考虑了泵内泄漏补偿控制,系统特性满足恒功率控制要求,控制精度较高参考文献1 张力平等.新型径向柱塞变量泵恒功率控制机构的方案比较分析. 太原重型机械学院学报,2003(2>2 王春行. 电液伺服控制系统. 北京:机械工业出版社,19893 王建森. 径向柱塞变量泵电液恒功率控制方式的探讨. 液压与气动,2004(3>通信地址!四川绵阳西南科技大学制造科学与工程学院"621010#(收稿日期:2005-03-24>近年来,随着商品混凝土的发展和混凝土搅拌车的推广应用,国内生产混凝土搅拌车的企业如雨后春笋般发展起来,8 m 3水泥混凝土搅拌车的设计技术也已成为行业探索的课题 我们对该车的上车液压驱动系统进行仿真,目的是为8 m 3搅拌车的设计制造提供一定的参照,同时也能为我们目前还没有太多成熟经验的超大搅拌容量搅拌车的设计制造提供参考经验1 仿真问题的提出和目的由于目前对于水泥混凝土搅拌车上车液压驱动系统以及各元件的选型,都是采用经验公式或是类比的方法,设计出的系统需经整车装配 试运行后方可得知系统设计的优劣性和经济合理性 如若发现设计不合理,则需改进设计并重新选型,造成设计周期过长 效率不高 经济性下降,情况严重时还会在试车时损坏元件,造成不必要的损失对此,我们提出在设计完成后先对系统做计算机仿真,初步了解系统运行时的各种特性,减少设计的盲目性,以确保试车时的安全性和稳定性,并缩短设计周期,提高经济效益通过对8 m 3水泥混凝土搅拌车上车液压驱动系统进行仿真,来获得相关的数据(系统实际最高压力 最大流量 液压泵及液压马达的实际压力 转矩和功率等,特别是减速机在启动和换向时所承受的最大转矩>,用以确保液压系统及各液压元件在各种工况下的安全性和可靠性,对系统设计时各元件的选型提供一定的参考长安大学赵铁栓蔡应强关键词!混凝土搅拌车液压系统AMESIM 仿真""!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"!!!!!!"!!摘要!利用仿真软件AMESIM 对8 m 3水泥混凝土搅拌车上车液压驱动系统进行了仿真 主要针对搅拌车在各种作业工况下系统的压力 流量 溢流量和各液压元件的输入 输出转矩以及减速机和搅拌筒的转矩等一系列重要参数做了分析,得出了搅拌车在不同工况和工况发生变化时,系统的压力 流量等的变化情况以及泵 马达 减速机所承受的载荷 同时对搅拌车工况改变时换向阀所需的换向时间进行调整,仿真出一系列马达转矩变化曲线,通过对比揭示了换向阀换向时间的大小对系统的稳定性和承载能力具有非常大的影响基于AMESIM 的混凝土搅拌车液压系统仿真52液.液压力2005(8)图!液压传动系统仿真建模图图"混凝土搅拌运输车液压系统原理图1. 主泵2. 辅助泵3. 手动换向阀4. 补油溢流阀5\6. 单向阀7\8. 安全阀9. 冲洗阀10. 马达11. 粗过滤器12. 散热器13. 精过滤器2 仿真软件简介仿真软件的名称是AMESIM 9是IMAGINE 公司于1995年推出的专门用于液压/机械系统的建模\仿真及动力学分析的优秀软件9该软件包含了IMAGINE 的专门技术9并为工程设计提供交互能力0AMESIM 为流体动力(流体及气体)\机械\热流体和控制系统提供一个完善\优越的仿真环境及最灵活的解决方案0AMESIM 使用户能够借助其友好的\面向实际应用的方案9研究任何元件或回路的动力学特性0作为设计软件包9AMESIM 为用户提供了一个完善的时域仿真O 包括线性分析及各种专业特性O 建模环境0工程师可使用已有模型和(或)建立新的子模型元件9来构建优化设计所需的实际原型0基于先进的数字积分器9AMESIM 求解器根据系统的动态特性9在17种可选算法中自动选择最佳积分算法9并具有精确的不连续性处理能力9AMESIM 这些独创的技术9保证了仿真的速度和精度03 仿真模型的建立为使我们的仿真具有普遍性和现实性9我们根据目前市场上各大企业所生产的8 m 3水泥混凝土搅拌车上车液压驱动系统的结构9选定目前比较常见的系统配置0#$"搅拌车液压系统原理!图""#$!搅拌车液压系统主要参数系统额定压力O Mpa O 25系统最高压力O Mpa O 35发动机额定转速O r/min O 2 100液压马达排量O mL/r O 70液压泵排量O mL/r O 70补油泵排量O mL/r O 18.03补油压力O Mpa O 2.5搅拌筒转动惯量O kg .m 2O0.863#$#仿真系统建模!图!"O 1O 因为AMESIM 软件系统中没有液控阀\液控泵等液控部件9所以在仿真过程中9我们采用直接信号加载方式9局部采用电控装置代替0O !O 发动机该软件只提供了带调控的和不带调控的两种方式的发动机0这两种发动机根据转速特性又可分为两类:恒速和变速O 变速响应方程为线性的O9均不符合搅拌车上车液压驱动系统所需发动机的要求9所以采用数学模型来代替0发动机的数学模型为转速相对负载转矩变化9具体数据根据额定转速为2 100r/min 的发动机的外特性来确定9取其右半段O 因为建立模型时不允许出现转矩朝相反方向变化9即转矩只能朝一个方向变化O0O 3O 变量泵由于搅拌车所采用的变量柱塞泵一般需要手动或电信号来控制其实现正转\反转以及零位共三个位置的工作9所以我们采用连续信号直接加载使液压泵实现不同的排量9从而实现不同的工况0O "O 减速机根据该软件所提供的元件9采用一个带转动惯53--液 液压力2005(8)图!进料工况仿真建模图"系统!换向阀"加载信号量的旋转负载和一级机械变速齿轮来模拟实际搅拌车中减速机的功能5 搅拌筒根据该软件所提供的元件 搅拌筒负载采用一端固定 一端旋转并可以通过加载固定信号来模拟搅拌筒的转矩功效来实现!系统加载仿真l 为了解搅拌车在空载启动后 整个系统在连续进料过程中的平稳性能 首先我们对连续进料工况单独进行仿真 建模如图3所示给系统一个斜坡信号 模拟进料过程中混凝土量 搅拌筒转矩 随时间成线性增加 并且给系统一个固定信号k 使得液压泵处于最大正排量 系统在100 S 后开始加载 依据实际搅拌车工况 进料过程仿真时间为l0 min从图4 图5 我们可以看出 随着混凝土的不断增加 马达转矩也呈线性增加 整个进料过程运转平稳 没有出现波动 所以泵和马达以及减速机的运转也很平稳 没有超过其承载能力 这同时也说明 由于进料过程比较缓慢 搅拌筒中的混凝土量变化不大 故系统运转较平稳 不会产生大的冲击2 假定在所有的工况中搅拌筒均为满载 对搅拌车的整个工作过程进行仿真 即给系统依次加载不同的信号来控制搅拌筒依次实现进料 搅动 以及反转卸料 最后停止对系统 换向阀 加载连续跳变信号 通过节流口大小控制跳变时间 以测试系统的动态性能和静态性能 信号跳变时间随时间成线性变化 从而获取系统最大承载能力以及系统的非线性变化度图6为信号加载图 图7"图10为仿真结果 从中我们可以看出 当加载信号发生跳变也就是搅拌车改变工况时 系统冲击较大 特别是在搅拌筒从静止启动向满载工况变化和从正向搅动到反向卸料时 系统的冲击最大 此时系统压力剧增 从而产生较大溢流 同时转矩的变化也非常大 马达最大转矩达到约360 N m 即搅拌筒的最大转矩约为54 000 Nm 为额定转矩的1.125倍 根据节流口直径与换向时间的关系 表1 不考虑系统的溢流 分别对系统作仿真 结果如下 信号加载如图6所示图#!搅拌筒转矩"信号加载图$马达转矩变化节流口直径 mm 0.76 1.05 1.6无节流口换向时间 S6.063.061.740.96表%节流口直径与换向时间的关系54液"液压力2005(8)图ll !图l4为仿真结果9其中曲线l \2\3\4分别代表换向时间为0.96 S \1.74 S \3.06 S \6.06 S 时马达转矩的变化情况0为了便于比较我们将4种情况表现在一张图上9再加以局部放大0很显然9节流口直径越大9换向时间越短 即响应时间越短 9转矩峰值越大9系统的冲击越大9这说明快速响应时系统的瞬态性能很差9较长时间才能达到稳定值9并具有非常大的超调量0在不考虑溢流的情况下9换向时间为0.96 S 时其最大转矩居然达到其额定值的2!3倍 很明显9我们可以通过延长换向阀换向时间9即延长响应时间9提高系统的瞬态性能9降低超调量9从而控制系统的最高压力和马达的转矩峰值9确保系统和各液压元件有较好的可靠性05 仿真结果与试验结果对比AMESIM 是专业流体仿真软件9其仿真的可信度经过实践检验是值得信赖的9因而仿真结果的可信度主要取决于系统建模的精确程度0由于在仿真建模过程中对系统作了一定程度的简化处理9如用直接信号加载方式取代液压阀的换向特性9用电控装置取代液控元件9将液压元件本身的过渡过程理想化9以及发动机数学模型的建立9这可能使得仿真结果更趋于理想化9但也有可能使得可信度下降9为了证明所建立模型的准确性9我们有必要将仿真结果与试验结果进行对比9图15为对比结果 换向阀换向时间为3.06 S 9图中虚线为仿真结果9实线为试验结果0从图15我们可以看出9仿真结果与试验结果还是基本接近的9这说明我们所建立的搅拌车模型基本上是合理的0从对比可知9试验结果要稍滞后于仿真结果9且转矩冲击的幅度也稍小于仿真结果9这说明我们建模时对系统进行的简化对结果有一定影响9使得仿真结果稍偏离实际值9在实际运用当中应当对仿真结果适当缩小和延时06 结束语通过对8 m 3水泥混凝土搅拌车上车液压驱动系统进行仿真9我们可以得出以下结论:1 给系统输入斜坡信号9我们可以得知系统图8系统流量!实线"变化和溢流量!虚线"变化图9马达转速变化图7泵的两端压力变化注#以上结果都为换向阀节流口直径为1.05mm $换向时间为3.06S 时得出%图10马达转矩变化55--液~液压力2005(8)图14第三个冲击波动的放大图图13第二个冲击波动的放大图图11马达转矩变化图12第一个冲击波动的放大图图15仿真与试验对比图的响应是快速~稳定的,也就是说搅拌车在整个进料过程中是平稳的;O 2O 在搅拌车满载的工况下,系统对阶跃信号的响应时间和系统的瞬态性能以及超调量是互相矛盾的,即相应时间越快,系统瞬态性能越差,超调量越大,从而系统也就越不稳定,反之亦然O 提高系统的稳定性是以牺牲系统的响应时间为代价的;O 3O 由于工况变化时,系统的冲击较大,这就对液压元件的耐冲击~耐高压性能提出了更高的要求,而减速机也必须在满足稳定工况作业的同时留有一定的转矩裕度,以抵抗换向时的转矩冲击;O 4O 因搅拌车对响应的快速性要求不是很高,所以我们可以通过延长换向时间,即增大响应时间,从而获得较好的瞬态性能和较小的超调量,即减小液压系统冲击~降低搅拌筒转矩峰值;O 5O 通过对仿真结果与试验结果的对比分析,证明了所建立模型的准确性,确保了仿真结果的可信度;O 6O 通过对8 m 3水泥混凝土搅拌车上车液压驱动系统进行仿真,我们可以看到液压系统的不稳定因素和不安全因素是出现在工况发生改变的时候,这对我们以后设计超大容量的搅拌车具有一定的指导意义O参考文献1 陆元章. 液压系统的建模与分析. 上海Z 上海交通大学出版社,19892 姚怀新. 行走机械液压传动与控制. 北京Z 人民交通出版社,2002通信地址!陕西省西安市长安大学雁塔校区研2003级三班"710054#O 收稿日期Z 2005-03-21O56基于AMESIM的混凝土搅拌车液压系统仿真作者：赵铁栓， 蔡应强， Zhao Tieshuan， Cai Yingqiang作者单位：长安大学刊名：工程机械英文刊名：CONSTRUCTION MACHINERY AND EQUIPMENT年，卷(期)：2005,36(8)被引用次数：9次1.姚怀新行走机械液压传动与控制 20022.陆元章液压系统的建模与分析 19891.简桃凤.李四中.王猛汽车起重机变幅液压系统性能研究[期刊论文]-建设机械技术与管理 2011(1)2.揭琳锋.刘蕾.李悦.成中书基于AMESim的混凝土泵车泵送系统缓冲功能仿真研究[期刊论文]-液压气动与密封 2010(10)3.刘涛基于AMESim混凝土泵车用液压缸仿真分析[期刊论文]-科技信息 2010(11)4.王晋之.曹捷.张斌.李春光一种汽车起重机用液压变量马达的性能分析和优化设计[期刊论文]-液压气动与密封 2008(5)5.任彦恒.吕建刚某型履带车辆液压助力变速操纵系统仿真[期刊论文]-军械工程学院学报 2008(1)6.高顺德.张明辉.王欣.李西红大型履带起重机回转液压系统仿真[期刊论文]-建筑机械（上半月） 2007(4)7.李云济.张大海.焦生杰基于AMESim的沥青洒布车开式液压系统仿真研究[期刊论文]-中国工程机械学报 2006(2)8.刘海丽基于AMESim的液压系统建模与仿真技术研究[学位论文]硕士 20069.张明辉大型履带起重机回转液压系统仿真研究[学位论文]硕士 2006本文链接：/Periodical_gcjx200508019.aspx。

混凝土结构仿真设计及其应用一、前言混凝土是一种被广泛应用于建筑、桥梁、水利工程等领域的材料，具有高强度、耐久性、灵活性等优点。

然而，在混凝土结构设计的过程中，由于其复杂性和不确定性，需要进行大量的试验和仿真来得到合适的设计方案。

本文将介绍混凝土结构仿真设计及其应用，包括仿真设计的基本原理、方法和工具，以及在实际工程中的应用。

二、混凝土结构仿真设计的基本原理混凝土结构的设计需要考虑多种因素，如载荷、材料、结构形式等，同时还需要考虑设计的经济性、安全性、可行性等方面。

由于混凝土结构的复杂性和不确定性，设计者需要利用计算机仿真模拟来得到合适的设计方案，这就是混凝土结构仿真设计的基本原理。

混凝土结构仿真设计的基本思路是将实际结构抽象成一个数学模型，并在计算机上进行计算，得到结构的受力、变形等信息。

这个数学模型需要考虑结构的几何形状、材料的物性、加载条件等因素，同时还需要选择合适的数值分析方法和计算工具。

三、混凝土结构仿真设计的方法混凝土结构仿真设计的方法主要包括有限元方法、有限差分法、边界元法等。

其中，有限元方法是最常用的方法之一，具有计算精度高、适用范围广、计算结果可靠等优点。

下面将简要介绍有限元方法的基本原理和步骤。

有限元方法是一种将结构离散化为有限个小单元的数值分析方法。

通过对每个小单元的受力和变形进行计算，得到整个结构的受力和变形情况。

有限元方法的基本步骤如下：1.建立有限元模型根据实际结构的几何形状和材料特性，选择合适的有限元单元，将结构离散化为有限个小单元。

每个小单元具有一定的形状、尺寸和节点数，可以用来计算该单元的受力和变形情况。

建立完有限元模型后，需要对模型进行验证和检验，以保证其准确性和可靠性。

2.确定边界条件边界条件是指结构的边界和加载条件。

在有限元模型中，需要对结构的边界和加载条件进行明确和确定。

边界条件包括结构的支撑和约束情况，加载条件包括结构所受的荷载和荷载作用的时间。

3.进行计算分析根据有限元模型和边界条件，进行计算分析。

仿真和建模课程设计作业
工业工程：2011级学号：1121040035 姓名：梁星海
课题：建筑施工中，混凝土浇筑过程中受混凝土凝固时间的限制，大体积混凝土一般必须在24小时浇筑完毕，汽车泵（80方/h)，地泵（45方/h)，搅拌车有6方，8方，10方。

浇筑一车混凝土的时间服从均值在7分钟-15分钟的指数分布。

5000方的混凝土，应该配备多少汽车泵，和地泵，搅拌车，使得浇筑时间最短？
模型：详见E:\D盘\12 同济大学工程硕士\2012年上半年\建模和仿真\1121040035-梁星海-混凝土浇筑情况.mox（已发）
报告分析：
首先是在搅拌车配备上，在不考虑机械配备情况下，6方，8方，10方，均可以，平均分配搅拌车。

但是每种车型都有，不经济。

以10方运输最经济，可确保最大限度利用机械设备。

机械设备的配备情况，按照浇筑量5000方，需要配备汽车泵至少三台，地泵一台以上，可以在24小时内，将5000方混凝土浇筑完毕。

此题目的瓶颈，分析主要是在搅拌车和机械的衔接上，尽可能的减少搅拌车的种类，并在开始的时候，尽量使用汽车泵和装载大方量的搅拌车，否则，局部有汽车泵供应能力不足的情况，或者是地泵泵送能力赶不上搅拌车运输的能力，出现窝工等待现象。

另外，还受现场条件和场地布置影响，实际的汽车泵和地泵数量还应该有余量，各增加出一台，以确保24小时内全部浇筑完毕。

基于EDEM的搅拌机混合均匀度仿真分析*王晓伟 陈庆照 王海洋山东建筑大学 济南 250101摘要：文中针对烧结砖用双轴搅拌机搅拌叶片不同安装角对搅拌混合均匀度的影响进行了仿真研究。

首先分析了物料颗粒性质及其搅拌中的碰撞运动，选择了合适的颗粒接触模型和颗粒模型，其次建立了3种搅拌叶片安装角的搅拌机模型，并利用EDEM仿真软件对搅拌混合过程进行了模拟仿真，对比分析了搅拌叶片不同安装角下的物料离散系数，得到搅拌叶片的最佳安装角度，此时物料离散系数最小，混合均匀度最好。

关键词：双轴搅拌机；EDEM；离散系数；均匀度中图分类号：TP391.9 文献标识码：A 文章编号：1001-0785（2023）16-0024-06Abstract: In this paper, the influence of different installation angles of mixing blades on mixing uniformity of double-shaft mixer for sintered brick was simulated. Firstly, the properties of material particles and the collision motion in stirring were analyzed, and the appropriate particle contact model and particle model were selected. Secondly, three mixer models with different installation angles of stirring blades were established, and the stirring process was simulated by EDEM simulation software, so as to compare and analyze the material dispersion coefficient under different installation angles of stirring blades and get the best installation angle of stirring blades with the smallest dispersion coefficient and the best mixing uniformity. Keywords:double-shaft mixer；EDEM；discrete coefficient；uniformity0 引言烧结砖由不同原料搅拌混合后烧制而成，原料混合均匀程度会严重影响烧结砖的烧成质量[1]。

基于DELMIA的搅拌车装配过程仿真研究作者：尹文生尹良管在林随着计算机仿真技术的不断发展与成熟，虚拟仿真技术的应用也越来越广泛，从飞机、船舶、汽车到电子生产处处可见仿真的身影。

虚拟仿真技术相较于传统的样机验证有着无法比拟的优势，传统的样机验证方式是在产品设计后，调用大量的设备与人员生产少量样机，利用样机对新产品设计合理性进行验证，这样会产生巨大的资源和时间浪费。

而如果采用在虚拟现实环境中对产品进行设计、生产、装配、使用和调试仿真，直观分析产品的可装配性，以及量化的人机工效分析和评估，对其装配工艺方法进行必要的调整和优化，这样可在完成更多分析验证的同时省去样机制造和验证的巨大资源和时间浪费，节省大量的物力、人力成本，并缩短大量制造和调试时间，提高企业的市场竞争力。

本文重点介绍在DELMIA平台上进行搅拌车的虚拟装配过程，并利用DELMIA的强大分析功能，对搅拌车的整个装配进行装配可行性分析和人因分析，由此可对搅拌车的结构设计以及装配工艺进行改进和优化。

1 DELMIA简介DELMIA是法国Dassault公司推出的一套数字化设计、制造、维护、数据管理的PLM平台，它提供目前市场上最完整的3D数字化设计、制造和数字化生产线解决方案。

DELMIA主要由3个部分组成，分别为DPE(DELMIA Proceaa EnSineer)、DPM(Digital Proceos of Manufacturing)和DELMIA/QUEST(Queuing Event Simulation Tool)，其中DPE 负责制定制造工艺和资源规划，DPM进行制造过程工艺仿真分析，DELMIA/QUEST进行生产线和物流过程的设计仿真分析，这3个相对独立的部分通过DELMIA的结构核心PPR(Procesa-Product-Resource) Hub连接到一起。

2 搅拌车的虚拟装配仿真基于DELMIA的仿真分析流程如图1所示，包括前期模型的构建、装配过程仿真、仿真分析与优化、结果输出。

基于人工智能的混凝土施工仿真原理一、前言随着现代科技的不断发展，人工智能技术已经成为了各行各业的热门话题，其应用范围也越来越广泛。

混凝土施工作为建筑行业中不可或缺的一部分，也可以通过人工智能技术进行仿真模拟，提高施工效率和质量。

本文将介绍基于人工智能的混凝土施工仿真原理和具体应用。

二、混凝土施工仿真的原理在混凝土施工中，人工智能技术主要应用于施工过程的仿真模拟。

具体而言，它可以模拟混凝土浇筑、振捣、养护等过程，预测施工中可能出现的问题并提前进行调整和优化。

其基本原理如下：1. 建立三维模型首先，需要建立混凝土施工的三维模型，包括建筑物的大小、形状、结构等信息。

这一步需要借助计算机辅助设计软件，如AutoCAD、Revit等。

2. 设定施工参数接着，需要设定混凝土施工过程中的各项参数，如浇筑速度、振捣时间、养护时间、材料配比等。

这些参数的设定需要结合实际工程情况和经验进行调整。

3. 运用人工智能算法在设定好施工参数后，需要运用人工智能算法进行仿真模拟。

利用人工智能算法进行计算和分析，可以预测施工过程中可能出现的问题，如混凝土裂缝、坍塌等，并提前进行调整和优化。

4. 生成仿真结果最后，通过人工智能算法生成仿真结果，包括混凝土浇筑、振捣、养护等过程的模拟效果。

这些结果可以直观地显示在计算机屏幕上，方便工程师进行观察和分析。

三、混凝土施工仿真的应用基于人工智能的混凝土施工仿真技术可以应用于多个方面，其中包括：1. 施工过程优化通过混凝土施工仿真技术可以对施工过程进行优化，提高施工效率和质量。

例如，可以通过模拟不同的材料配比和浇筑速度，预测混凝土的坍塌性能，并选择最优方案进行施工。

2. 施工安全预警利用混凝土施工仿真技术可以提前预警施工中可能出现的安全隐患，如混凝土裂缝、坍塌等。

这可以帮助工程师及时采取措施，保证施工安全。

3. 教育培训混凝土施工仿真技术还可以用于建筑行业的教育培训。

通过模拟不同的施工过程和参数，可以培养工程师的实践能力和解决问题的能力。

1 离散单元法基本算法及主要的接触模型1.1 离散元算法离散单元法是由美国教授CundallP.A.提出，是以分子动力学理论为基础的一种用来解析单个颗粒离散元物料的研究方法。

离散单元法首先借助离散元法的基本运动方程（1）以及公式（2）求解出力的值，然通过牛顿第二运动定律求解出单元的加速度，最后对加速度积分求解出单元的速度和位移。

离散元法的基本运动方程：md 2u/dt 2+F R +F A +F =0 (1)式中：m — 颗粒质量；u — 颗粒位移；F R — 线性阻尼力；F A — 接触力；F —不平衡力。

公式（2）中，将分解为切向接触力和法向接触力，如下式所示：F An =F An （k n ，δn ，δn ）F AS =F AS （k S ，δn ，δS ）(2)式中：k n — 法相接触刚度；k S — 切向接触刚度；δS —切向相对位移；δn —法向相对位移。

由牛顿第二定律，第颗粒在时刻的转动惯量为：m i i（t ）= F i（t ）I ii （t ）= T i （t ）(3)式中：m i — 质量；i— 平动加速度；F i — 合力；Ii — 转动惯量；i— 角加速度；T i —合力矩。

依据中心差分法，可算出t+ ∆t/2时的平动速度i(t +∆t/2)和角速度i(t + ∆t/2)为：i (t +∆t/2)=i(t -∆t/2)+i(t )∆ti(t +∆t/2)=i(t -∆t/2)+i(t )∆t(4)式中：∆t — 时间步间隔；i(t -∆t/2) — 在t -∆t/2时的平动速度；i(t -∆t/2) — 在t -∆t/2时的角速度。

求出在t +∆t 时的颗粒位移u i (t +∆t )和角位移θi (t +∆t )分别为：u i (t +∆t )=u i (t )+i(t )∆tθi (t +∆t )=θi (t )+i (t )∆t(5)式中：u i (t ) — 平动位移；θi (t ) —角位移。

基于虚拟试验场的混凝土搅拌运输车结构件疲劳仿真分析Xia Xuewen;Wang Chengkai;Lei Xinjun【摘要】文章以混凝土搅拌运输车为研究对象,使用MSC Nastran计算车架模态中性文件,MSC Adams搭建整车多体动力学模型和虚拟试验场,同时进行应力和振动测试,验证整车模型,进而输出载荷文件至MSC Fatigue,进行车辆结构件和焊缝疲劳仿真分析,疲劳预警区域基本与曾开裂区域一致,此方法可指导新车型结构件设计和优化老车型结构件,且能拓展至其他车型和基于客户路谱的疲劳分析.【期刊名称】《汽车实用技术》【年(卷),期】2018(000)023【总页数】4页(P216-219)【关键词】虚拟试验场;疲劳仿真;混凝土搅拌运输车;动力学;应力;振动【作者】Xia Xuewen;Wang Chengkai;Lei Xinjun【作者单位】;;【正文语种】中文【中图分类】U469.6+5引言混凝土搅拌运输车（以下简称搅拌车）承载重，运行工况复杂，新车型量产前进行至少两个月规定里程试验场的强化路试验。

强化路环形试验场包括扭曲路、鱼鳞坑路和搓衣板路，扭曲路为试验场典型路况，对车架结构件损伤最大，结构件开裂发生在该疲劳扭转工况。

为了减少强化路试验时间和在设计阶段发现欠设计结构件，很有必要进行搅拌车结构件疲劳仿真分析，本文以某四轴搅拌车为研究对象，使用 MSC软件公司仿真工具搭建整车多体动力学模型进行虚拟试验场仿真分析，同时进行应力和振动试验验证，进一步进行疲劳仿真计算，预警结构件欠设计区域，技术路线如图1。

1 整车多体动力学建模1.1 结构件模态应力恢复理论搅拌车大型结构件包括主车架、副车架、前台、后台和扶梯，如果采用常规有限元方法模拟结构件的变形，会使得结构件自由度多，方程阶数高，计算成本巨大，且结构的响应由低级模态控制，不必为少数低阶模态去求解整个结构的高阶动力学方程，因此本文选择模态综合法模拟结构件的变形，而 Craig-Bampton方法是固定界面模态综合法中最具代表性的一种方法。

混凝土搅拌车搅拌实验系统仿真设计学生姓名：班级：指导老师：摘要：混凝土搅拌运输车是用于解决商品混凝土运输的运输工具。

它兼有载运和搅拌混凝土的双重功能，可在运送混凝土的同时对其进行搅拌或搅动，因此能在保证输送的混凝土质量的同时适当延长运距(或运送时间)。

所以大力发展商品混凝土和搅拌运输车有明显的社会效益和适用价值。

而我国混凝土运输车起步较晚，到70年代才开始试生产。

目前，搅拌运输车的理论研究及生产在我省及整个西北地区均处于空白。

因此搅拌运输车的理论研究及开发势在必行。

搅拌运输车的搅拌筒之所以具有搅拌和卸料的功能，主要是因为拌筒内部特有的两条连续螺旋叶片在工作时形成螺旋运动，从而推动混凝土沿搅拌筒轴向和切向产生复合运动的结果。

因此两条叶片的螺旋曲线的形式及结构直接影响搅拌筒的工作性能。

本论文基于物料在螺旋叶片上的搅拌出料机理对螺旋叶片的工作原理、主要技术参数进行理论分析和计算，同时对前锥段、后锥段的螺旋叶片进行展开设计；对拌筒进行几何设计。

搅拌筒既是搅拌运输车运输混凝土的装载容器，又是搅拌混凝土的工作装置。

几何设计是搅拌筒结构设计的基础，它包括几何容积计算、外形尺寸的确定、搅拌筒有效容积及满载时重心位置计算。

为使混凝土搅拌运输车的搅拌装置系列化，以满足用户要求，借用计算机程序语言对其进行设计。

基于功率键合图的建模方法，利用大型软件Matlab的仿真工具箱Simulink，对混凝土搅拌运输车液压系统进行设计分析，同时建立系统动态仿真模型，用此来模拟液压系统工作过程，更好地反映系统中各输出变量随输入变量的变化关系。

尤其是对辅助泵调节斜盘角度系统、变量主泵控制系统及恒速控制系统进行详细的分析，为液压系统的进一步优化设计提供有益的借鉴。

关键词：混凝土搅拌运输车拌筒液压系统功率键合图几何设计数学模型螺旋叶片动态特性展开仿真指导老师签名：Design of the Structure of the Truck Mixer and DigitalSimulationof its Hydraulic SystemStudent name: ClassSupervisor:Abstract:The truck mixer is a vehicle for transportation concrete. It is fulfilled two actions,conveying concrete and mixing concrete. These actions not only ensure the quality of the concrete, but also make the conveying distance longer. But in thenorthwest area of our country, research on the field of the truck mixer is little. So the truck mixer must be developed strongly in order to meet the need of the risingconcrete market. Three important parts are studied in this thesis. Firstly, thehelix-vanes of the truck mixer are designed following the principles of the flowing state of the concrete on the helix-vane. Secondly, the drum of the truck mixer is designed base on its working characteristic. Thirdly, with the widely used soft ware package SIMULINK the mathematic models of the hydraulic system driving the truck mixer are established on the found of the theory and method of power bond graph. The dynamic characteristics of the hydraulic system are simulated numerically, and some significant results are presented.Key words:Truck Mixer Drum Spread Hydraulic SystemMathematic Models Structure Design Helix-vanesPower Bond Graph Dynamic Characteristics SimulationSignature of Supervisor:目录1.绪论1.1混凝土搅拌车的介绍 ------------------------------------------ 4 1.2课题研究背景 ------------------------------------------------ 6 1.31.4本文研究内容及方法 ------------------------------------------ 82.搅拌筒的结构设计2.1搅拌筒的工作原理 ------------------------------------------- 10 2.2搅拌筒的整体构成 ------------------------------------------- 10 2.3拌筒主要结构尺寸参数的确定 --------------------------------- 11 2.4切割法求装载容积 ------------------------------------------- 13 2.5积分法求装载容积 ------------------------------------------- 14 2.6搅拌筒几何容积计算 ----------------------------------------- 182.7满载时拌筒的重心位置 --------------------------------------- 183.驱动功率的计算3.1搅拌力矩曲线 ----------------------------------------------- 19 3.2驱动阻力矩计算 --------------------------------------------- 193.3搅拌筒驱动功率的计算 --------------------------------------- 234.螺旋叶片的设计及仿真4.1螺旋叶片上螺旋角的确定 ------------------------------------- 24 4.2搅拌叶片的母线方程 ----------------------------------------- 27 4.3搅拌叶片设计 ----------------------------------------------- 29 4.4搅拌叶片的仿真设计和模态分析 ------------------------------- 33 4.5搅拌叶片结构应力分析 --------------------------------------- 37参考文献------------------------------------------------------ 43致谢 ----------------------------------------------------------- 44附录 ----------------------------------------------------------- 441.绪论1.1 混凝土搅拌车的介绍商品混凝土的发展从根本上改变了传统上工地自制混凝土，用翻斗车或自卸卡车进行输送，就近使用的落后生产方式，建立起一种新的生产方式，即许多施工工地所需要的混凝土，都由专业化的混凝土工厂或大型混凝土搅拌站集中生产供应，形成以混凝土制备地点为中心的供应网。

混砂车搅拌罐试验模型相似设计及数值模拟周思柱;袁新梅;黄天成;王勇;刘奔;华剑【期刊名称】《中国科技论文》【年(卷),期】2014(000)005【摘要】The object of this study is the mixing tank of fracturing blender truck.In order to reflect the mixing effect of test stir-ring tank in real stirring tank,the mixing power in a unit volume is treated as the scale-up criteria,and the mixing model is estab-lished by the principle of geometric similarity.The structural size of the mixing system in 1:1 and 1:4 cases is discussed by using flow field analysis software FLUENT.In order to be as close as possible to the actual conditions,we used continuous sediment mixing to make the mixture reach a discharge process while mixing.As a result,the speed relationship between the test mixing tank and the fracturing blender truck mixing tank is established,which makes the test results be better applied to fracturing blender truck stirring tank.%以混砂车搅拌罐为研究对象，为了将试验搅拌罐的混合效果在混砂车搅拌罐中重现，以搅拌罐单位体积的搅拌功率作为放大准则，用几何相似的原则分别建立了结构尺寸为1∶1和1∶4的搅拌模型。