In response to the low design efficiency caused by the numerous design parameters of existing shock absorbers, this research presents the design of an efficient software tool for obtaining the external characteristics of Continuous Damping Control (CDC) shock absorbers. Firstly, a mathematical model for the damping force of the shock absorber was established based on principles from fluid dynamics, elasticity mechanics, and throttle orifice models in the rebound and compression valve systems. Secondly, a Graphical User Interface (GUI) was developed to visualize the external characteristics and conduct simulation studies of the CDC shock absorber. Finally, experiments were performed on a shock absorber test bench to validate the external characteristics of the CDC shock absorber using initial structural parameters. The GUI software interface enables direct adjustment of the shock absorber's structural parameters and signal excitation, thereby enhancing the practical efficiency of the shock absorber. A comparison between simulation and experimental results reveals that the relative error rate is generally high when the velocity amplitude is 0.052m/s, with a maximum relative error rate of 24.44

Background: The electro-hydraulic servo system has the advantages of high stiffness, fast response speed, high precision and power-to-weight ratio. Objective: In this patent, an adaptive robust control strategy based on friction compensation is proposed for insufficient control accuracy due to a large number of nonlinearities and uncertainties in the system. Methods: In this patent, the mathematical relationship between the physical quantities of the valve-controlled cylinder is analyzed. Then the mathematical model of valve controlled cylinder considering the main nonlinearity and uncertainty of the system is established. The fuzzy proportion-integral-derivative, deterministic robust, and adaptive robust single-cylinder trajectory tracking controllers are designed and the tracking performance of different reference trajectories is analyzed by MATLAB/Simulink software. Results: In this patent, all the three controllers can track the reference trajectories smoothly. Adaptive robust control strategy can make the uncertain parameters of system converge and approach truth value. Conclusion: In this patent, the adaptive robust control strategy has the function of online parameter adjustment. When tracking accuracy is taken as the index, its tracking effect is better than fuzzy proportion-integral-derivative and deterministic robust.

为了探究轴配流液压脉冲发生器的内泄漏影响因素,利用Solidworks建立简化的间隙流场模型,通过ICEM进行网格划分,使用Fluent软件进行流体仿真,以开度、高压侧间隙高度、偏心量、入口压力作为变量,计算不同高压侧间隙下的周向、轴向的泄漏量并进行比较,得到了转阀内泄漏变化的规律.结果表明:高压侧间隙高度是影响内泄漏量的主要因素,且周向泄漏量大于轴向;低压工况下,各偏心量的内泄漏量基本不变,而高压时偏心量对内泄漏量有明显影响;开度对内泄漏量的影响取决于腔体窗口是否与阀芯高/低压侧连通,腔体窗口的通断使内泄漏量产生约0.5 L/min的突变,不利于保持内泄漏量的稳定;入口压力的升高总使内泄漏量增加,在同样的压力下,高压侧间隙高度或偏心量越大,内泄漏增量越大.

将终端滑模控制(TSMC)策略应用于永磁同步电机(PMSM)位置控制,以提高系统输出响应性能.基于终端滑动模式技术,设计一种新的有限时间收敛的干扰观测器以估计PMSM的集体不确定性,包括系统参数不确定性和未知的外部负载.与渐近收敛控制器不同,TSMC保证系统状态误差和观测器估计误差在有限时间内能收敛到0.结果表明:与PID控制和传统反步法控制相比,所提出的控制器控制效果更好.

利用AutoForm软件对汽车前罩锁销加强件的冲压成形过程进行了数值模拟分析.通过模拟结果发现模拟过程中潜在的问题,缩短修模周期,以减少实际生产过程中的残次品,提高产品合格率.

For the rear side inner panel of an automobile, its forming process was analyzed, and the rapid modeling and simulation of drawing die-surface were conducted by Autoform to predict the cracking, excessive thinning and wrinkling defects in the drawing process.Then, the refined modeling design of die-face was built by NX with the result of forming and relevant experience, and the whole process simulation and springback compensation of optimized die-face were carried out. The results show that the die-face after refined modeling design successfully solves the drawing cracking, excessive thinning and wrinkling defects, and the springback is controlled by compensation. The maximum thinning rate is reduced from 0. 405 to 0. 22, the maximum wrinkle coefficient is reduced from 0. 11 to 0. 008, and the maximum springback is reduced from 1. 936 mm to 0. 315 mm. Finally, the stamping experiment is carried out, and the obtained parts are qualified which verifies the effectiveness of the refined modeling design of die-face.

Thermal forming processes and blank-holder force (BHF) technology can both effectively improve the formability of high strength steel (HSS). However, whether the BHF technology is applicable at elevated temperature has yet to be researched. So, in this paper, to evaluate its applicability, BHF window was selected and its size was observed. The cylindrical cup was selected as the research object and its theoretical BHF windows at temperatures from room temperature (RT) to 400 °C, based on plastic theory, were constructed and verified by experiments. Then, main factors contributing to the change of BHF window as temperature rose were analyzed and effective methods for expanding BHF window size were studied. The experimental date, according well with the theoretical BHF windows with the exception of that at temperature of 300~350 °C because of the “blue brittle,” prove the validity of theoretical BHF window. The size of BHF window kept shrinking as temperature rose, which means that it will be more difficult to implement BHF technology at higher temperatures. Initial diameter of blank, coefficient of friction (COF) between blank and die surface and material property are the main factors that affect the size of BHF window at RT or elevated temperatures. Therefore, certain temperatures possibly resulting in brittle fracture of blank should be avoided. Then, reasonable blank sizes and reducing COF could provide a reasonable size of BHF window and make implementing BHF technology in thermal sheet-forming feasible.

In order to meetthe blank holder force (BHF) synchronously chapging with stroke and position,a kind of two stages adjusting control system ofBHF forthe hydraulic press was proposed.The dual-loop control of hydraulic cushion force was realized based on electro-hydraulic proportional technology and PID.Through installing the force sensor on the special ejector rod,the adjustment of two stages ejector rod force was achieved.The system was verified by computing ofMATLAB / simulink software and box part drawing experiment.The results show that the response rate,the control stability and control accuracy,of the system can meet technical requirements.

以油箱盖板为研究对象,利用Dynaform有限元软件模拟了油箱盖板的拉深成形过程,分析了板料拉深成形过程中的起皱与拉裂等缺陷,选取模具间隙、冲压速度以及压边力3种工艺参数进行正交试验及参数优化,通过正交试验的极差分析得出影响油箱盖板最大减薄率的主次顺序为:模具间隙、压边力、冲压速度.此外由方差分析可知模具间隙及压边力对最大减薄率的影响显著.模拟结果表明,油箱盖板拉深成形的最优工艺方案为:模具间隙1.5t,冲压速度3000 mm·s-1以及压边力60 kN,其零件的最大减薄率及最大增厚率分别为13.23％与11.12％.采用拉深模具对优化后的工艺方案进行实验验证,零件的最大减薄率及最大增厚率分别为14.87％与12.64％,模拟结果与实验结果比较吻合,且油箱盖板的成形质量较好.

In solid laser shock forming of corrugated diaphragm,there are several problems in central part of the dia-phragm,such as producing reverse plastic deformation and even occurring fracture.To solve those problems,numerical simulation is applied to explore hollow laser shock forming of the diaphragm.Effect of hollow laser spot on diaphragm formability is researched through analyzing section contour and thickness distribution of the diaphragm after shock forming.The result shows that when conducting hollow laser shock forming of corrugated diaphragm,reverse plastic de-formation in central part of the diaphragm can be effectively reduced by adopting appropriate inner diameter of hollow laser,which makes the diaphragm fit die more tightly.Thickness distribution of the diaphragm after shock forming can also be improved with appropriate inner diameter,which avoids facture in central part of the diaphragm as a result of severe thinning.

The process of vacuum forming is introduced in this article as well as the key technology of vacuum forming,including establishment of motion function and prediction of forming time.A vacuum mould for refrigerator liner is taken as an analyzing example to analyze the process of vacuum forming by numerical simulation,based on Polyflow software,which results show that the blowing time is the key factor to control the quality of products.If blowing time is too short,thinning in local or uneven will result,while if it is too long,local wrinkles and folds may occur.By combining numerical simulation technology and motion functions the optimization for forming technology is realized.

The tensile tests of DP590 dual-phase steel tailor-welded blanks were carried out at different temperatures and strain rates. Quantitative analysis of metallographic was utilized to study the microstructure evolution of the base metal area and the weld zone of the tensile fracture. By combining the microstructure evolution model with the secondary development technologies of ABAQUS, the microstructure evolution of dual-phase steel tailor-welded blanks was simulated during warm tensile tests. The results show that, with the temperature increasing and strain rate decreasing, the dynamic recrystallization volume fraction of ferrite increases, and the martensite transform into equiaxed ferrite gradually. The results of microstructure simulation are in good agreement with experimental results.

Adhesion is a peculiar phenomenon of micro/nano-machine.When the strength of the component's material meets the demand,the adhesion and friction in the micro/nano-machines are the main cause of their failure.To overcome or reduce adhesion has become the hotspot in the micro/nano-electromechanical systems(MEMS/NEMS) research field.The adhesion issue in the micro/nano-machines is introduced.The mechanisms of adhesion and various adhensive models used in adhesive contact are analyzed.The micro/nano-machines' design principle of anti-adhesion using surface energy method and asperity integral method is illustrated.Various anti-adhesion methods such as release dry processes,real contact area reducing,and surface energy reducing,are presented.

The motion process of progressive blanking and drawing dies was analyzed and a coordination design was implemented by using movement simulation technology and motion functions,in which way precision multi-position progressive dies can have a longer service life.A further study on the structural motion of precision progressive dies indicates that coordination of complicated structural motion system should be solved for the dies.

Friction and wear tests and some swinging experiments were done to compare the friction and wear behavior of some materials used as the bottom pintles materials under both water-lubricated and grease-lubricated conditions. The wear mechanisms were discussed, some mechanical tests were done, and the material with better tribological properties was selected for the future Bench testing. The results show that a new material FZ5 (3) has good friction and wear behavior in friction and wear tests, and has the best tribological properties in the swinging experiments. Its good mechanical properties are proved by the mechanical tests such as rigidity tests, strength and ductility tests.

Under the environment of the software Pro/E, the paper studies the problem of creating models and design for three dimension fixtures, mainly includes creating the database of standard parts by family table, quickly designing and assembling fixtures by relation expression and simplified representation,calculating the mechanical parameters of parts such as stress and strain by the finite element method ,structurally optimal design and so on.

By using software ANSYS this paper calculates the contact stress and strain distribution within the mushroom head and the cap uniformly loaded in the bottom hinge of the ship gate. The effect of loaded area, friction coefficient, ball radius and matching gap on contact deformation were studied. The calculated data show that increasing the contact area between the pair is the most effective measure of decreasing the contact stress. This paper supplies the optimal design of part structure with data.

The common softwares used in numerical simulation of sheet metal stamping by finite elˉement method are introduced.With the automobile body metal sheet(box-shaped)as an example,the modeling method,parameter setting and simulation process with the software DYNAFORM-PC are introduced in detail.The causes of common forming defects such as wrinkling and breaking are analyzed.The multi-process drawing simulation method by means of the”ˇ.din”format file and the reversed simulation method used to define the blank shapes of complicated parts are introduced.The items such as improving the computation accuracy and efficiency by the technique of selft-adaptive re-divided meshes and ensuring the quality of complicated stampings by properly setting the drawing beads to regulate and control the sheet flow speed are discussed.

覆盖件模具的设计和制造是开发汽车新车型的"瓶颈"环节.介绍了产品装配模型并对其进行了描述,然后应用基于特征的三维参数化建模技术,针对某一几何拓扑关系类似的系列覆盖件产品中的一典型件,建立其参数化模具结构装配模型并实现模具结构的变形设计,最后以汽车前框架下横梁零件为例进行相关拉延模结构变形设计.结果表明,应用本文提出的设计方法,可以极大提高覆盖件模具结构的设计效率.

介绍了 DYNAFORM- PC软件的组成、功能和钣金成形模拟的一般步骤,结合油底壳和铰链加强板的模拟分析,提出了确定复杂冲压件落料毛坯的模拟逆推法,并介绍了提高模拟精度和计算效率的局部网格加密、局部区域试算以及简化所建模型等模拟技巧.