研究压发装置的精确建模与产品性能优化问题.基于绝对节点坐标方法的缩减板单元对压发装置电路板进行建模,通过实验确定电路板的材料参数及支撑弹簧与触发装置的非线性刚度特性,采用非线性力–位移关系建立了支撑弹簧与触发装置力学模型,搭建了压发装置结构的精确有限元模型;设计了压发装置加载实验系统,采用实验数据验证了上述有限元模型的正确性.根据目标触发载荷范围,优化了压发装置中支撑弹簧的刚度及长度参数.数值模拟直接指导了压发装置参数设计,并已成功应用于型号研制.

During the launch process of the membrane solar sail for deep space exploration mission， the membrane structure presents significant asymmetric characteristics under tension and compression. The dynamic behavior of the system shows strong nonlinear characteristics，which brings great challenges to the dynamic modeling and simulation calculation. Based on the Absolute Nodal Coordinate Formulation （ANCF）， integrating the tension field theory and the elasticity theory of different moduluses, the accurate tangent stiffness matrix of the element was derived， and a calculation method of ANCF membrane element considering different moduluses was proposed. On this basis, the first kind of Lagrange equation was used to model the dynamics of membrane solar sail，the dynamic equations were solved by the generalized-α algorithm with controllable numerical dissipation，and the influence of different structural design parameters of solar sail on its deployment dynamic characteristics was analyzed. The simulation results verify the stability and efficiency of this method in dealing with space membrane problems，and provide theoretical guidance for the system design of large sail membrane structures.

建立 SCARA机械臂的动力学微分方程，利用基于模型的解耦方法，并使用 DAMA Robotics 工具箱搭建了SCARA机械臂的仿真平台。在进行稳定性分析后，对该类机械臂进行轨迹规划与图形仿真。最后根据仿真结果对机械臂的性能指标进行了评估。结果表明该工具箱是快速搭建机械臂控制仿真系统和进行图形仿真的有利工具。

This paper analyzes the response of an infinite viscous-elastic half-space excited by the moving loads of different depths.To obtain the two-dimensional analytical solution of the viscous-elastic half-space due to the moving loads of different depths,the Laplace transformation and relative coordinate transformation were utilized.Then,two-dimensional infinite integration was calculated by employing the inverted fast Fourier transform and coordinate transformation to improve the operational efficiency.Further,the effects of different depths and different velocities on the surface response were analyzed.It is found that the significant asymmetry of displacement appears when the moving loads exceed the super-Rayleigh wave velocity on the surface.

力学实验教学中普遍存在的仪器和师资不足的问题严重影响了实验教学效果.本文发展了一套基于虚拟现实技术的力学虚拟实验系统,不仅能仿真实验结果,而且能仿真实验仪器和实验操作过程.系统可实现光弹性、电子散斑干涉、几何云纹、投影条纹、数字图像相关以及应变片实验共6个实验的仿真模拟.力学虚拟实验系统可作为常规实验力学教学的重要补充,在很大程度上缓解实验力学教学中存在的问题,改进教学效果.

A rule of response of an infinite viscous-elastic half-space stimulated by the moving loads of different speeds is outlined in this paper. In order to obtain a three-dimensional analytical solution of the Viscous-elastic half-space with the moving loads of different speeds, the Laplace transform and relative coordinate transformation in cylindrical coordinates are used. Then, the IFFT and relative coordinate transformation are used to solve two-dimensional infinite integration which can greatly improve the operational efficiency. The rules of responses of different velocities from the results by using the principle of dynamics and energy dissipation are also analyzed and induced in this paper, and obtain the incentives of displacement distortion by the super-Rayleigh wave velocity at surface. The results could be referred in improving the practical security in the project.

In this paper, a relationship is obtained between the best hitting point of the baseball and the natural frequency and the modal shape of the baseball bat through a finite element model. Assume that the material of the baseball bat model is linear elastic, and both ends of the bat are traction free, as is consistent with the actual situation, then we may discuss the ＇corking＇ of the bat （digging a cylindrical cavity at the head of the bat, putting a cork or rubber into it, and then covering it with a wood cap） or the use of metal bats. Both methods can increase the effect of ＇the sweet point＇. The validity of the model is verified by experiments.

用复合运动的方法推导了刚体在固定曲面上作平面纯滚动时接触点加速度的一般公式,该方法较简便严谨.

In this paper, we investigate a kind of multilayer cantilever microactuator (MCMA) actuated by Joule heating. The microactuator consists of three film layers, titanium, silicon dioxide and silicon. In light of non-uniform temperature distribution along the MCMA's length, an electro-thermo-mechanical analytical model is developed. The general analytical expression relating tip deflection with an applied voltage, the film thickness and the applied load at the tip is derived. The small deflection (less than 15%) is considered in the model. To evaluate the applicability of the analytical model, the analytical solution is compared with that from 3-D finite element analysis (FEA) and experimental results. The reliability of the analytical model is both device-dependant and temperature-dependant. In this study, the largest error of analytical model against FEA model and experimental data are approximately 13 and 31%, respectively.

在刚体一般运动的教学中,角速度是学生接受起来比较困难的一个概念,通过矢量运算引入这一概念,为角速度的教学提供了一种新的简单方法.

The teaching reform of class "Experimental Stress Analysis" performed by Experimental Center of fundamental mechanics of Beijing Institute of Technology is introduced. The student- oriented independent experiment is adopted in the new teaching mode. The experiment in the class is accomplished totally by students themselves, including project selection, designing, manufacturing, operation and summarizing. The better teaching effects can be obtained by new teaching mode , because the ability of students in many aspects can be exercised in the class study.

记述了我国分析力学著名专家、国家教学名师奖获得者、北京理工大学教授梅凤翔在教学、科研及为人师表方面的事迹和在教育事业上孜孜以求的进取精神。

The finite segment method, a discrete coordinate method for a flexible beam, was extended to a regular flexible plate,which is regarded as a multi-rigid bodies system with many compliance (stiffness、damping) joints. The basic idea and theoretical background of the discrete coordinate method were expounded, and the dynamic equation was built by Newton-Euler method. In virtue of finite element software and dynamic simulation program, this paper proved that the discrete coordinate method can be used for dynamic analysis of multi-body systems with regular flexible plate undergoing nonlinear deformations.

Firstly introduced some methods of building flexible bodies in ADAMS software.A multiple rigid-body model of solar panels was established in ADAMS/View 2005.And then the flexible panel was obtained by one method.With the new functionality in ADAMS/VIEW 2005,the rigid panel can be swapped to the flexible panel directly.Finally the simulation was carried out and simulation results were analyzed comparatively with the help of ADAMS/Postprocessor,the compliance of solar panels which affected the stretching process was discussed.

一、整合教学体系,加大改革力度 1997年,我们将工程力学课群教学体系和教学内容改革的目标定为:对工科力学课程进行整合,以力学的基本概念和基本原理为主线,重组教学内容,优化课程体系,改进教学手段,加强力学基础,突出工程应用,能反映近现代力学的某些发展,将课程体系和教学内容的改革反映在教材中,并着手编写新体系的<工程力学>教材.

The mathematical models of docking dynamics in the process of capture are established for two spacecrafts with inner guide petal peripheral docking mechanisms. The docking system is simplified into the initiative spacecraft, the passive spacecraft and the initiative capture annulus. Compared with the spacecraft, the initiative capture annulus has much less mass. So its mass and moment of inertia are omitted in the process of modeling. Only its geometry character is considered. The inaccurate factor in introducing insert quantity is eliminated through the way of calculating contact force with restriction equation. The docking strategy and design parameters of buffer, such as relative displacement, velocity and rotation of docking mechanisms and displacement and rotation of buffer, interacting force are obtained through simulation calculation. Thus docking dynamics can be understood better and an important reference is provided for the design of buffer and docking mechanism.

This survey article gives a critical review of some recent research of impact dynamics of flexible multi-body systems, including the description of the dynamic equations of flexible multi-body systems, the modeling for the impact and numerical algorithm. This paper also summarizes some developments in the simulation of human biodynamic modeling. The trend of the impact dynamics of flexible multi-body systems is discussed at the end of this paper.

This paper consider a solution to the problem of moving a robot manipulator with minimum cost along a specified geometric path.The optimal traveling time and the minimum mechanic energy of the actuators are considered together to build a multiobjective function.The dynamic equation is considered when the mathmatical model being built.The results of the multiobjective function depend on the weighting factors of the time and energy,and an algorthm is developed to optimize the function with physical constraints.Results are illustrated by means of a example of a six d.o.f manipulator.

理论力学是一门演绎性很强的重要技术基础课,它不仅是整个力学学科的基础,也是许多工科专业学习后续相关课程和将来从事科学技术工作的必要基础.理论力学以理论的系统性与应用的灵活性为特点,可以较好地培养学生的逻辑思维能力、抽象简化能力、实践应用能力和初步的科学研究能力.

通过对偶数、对偶矢量、对偶角、对偶质量运算符、矩积运算和矩积导数描述了简洁紧凑的开环多刚体系统的拉格朗日方程,并给出了一个算例.