高温(火灾)条件下钢结构材料模型及钢构件的单元刚度方程

在高温 (火灾 )条件下钢结构材料力学性能试验研究的基础上 ,建立高温下钢材的屈服强度 ,极限强度、弹性模量和极限应变等力学性能随温度变化的力学模型 ,利用广义clough模型 ,对平面钢框架进行分析 ,建立高温 (火灾 )条件下框架梁、柱杆件的单元刚度方程。     

Dynamic stiffness for thin-walled structures by power series

INTRODUCTION Thin-walled structures have considerable tech-nological importance in many situations of engi-neering practice. The rotary and warping inertia terms should be considered in the analyses of thin-walled structures (Alwis and Wang, 1996), although it is difficult to obtain the analytical solutions of govern-ing differential equations, especially of thin-walled frame and spatial twisted structure. The finite element method (FEM) is widely used for vibration and sta-bility analy…     

汽车传动轴减振器静动刚度测试分析

论述了在用MTS810材料试验机进行静动态性能测试的原理及方法,并对三种汽车传动轴减振器试件分别进行静刚度、动刚度特性测试。测试结果表明,这种方法简单、有效。试验结果为汽车传动轴减振器的改进提供了参考依据。     

客车车身骨架用铝合金型材的结构设计

车身骨架作为客车的主要承载件,其轻量化对客车节能减排具有重要作用.本文以客车骨架用铝合金型材为研究对象,以车身骨架用型材的弯曲刚度和扭转刚度为指标,利用CAE分析技术分析铝合金型材代替钢的可行性.结果表明:增加壁厚和增大截面尺寸均能提高铝合金型材的弯曲刚度和扭转刚度.客车车身骨架选用截面尺寸为52 mm×56 mm,壁厚为2.4 mm的铝合金型材,其刚度能够达到40 mm×40 mm×2 mm钢制方管的刚度指标,且实现减重27.5%.计算结果可为客车车身骨架用型材设计提供参考.     

Vibration response analysis of 2-DOF locally nonlinear systems based on the theory of modal superposition

1 Introduction ? Low frequency vibration has an important effect on body comfort and on the fatigue of a vibrating system. Nearly all actual vibrating systems are nonlinear. However, nonlinear behaviors are not always observed in the system dynamics. Thus…     

椭圆弹性铰链的特性分析

对具有任意角度椭圆凹槽的弹性铰链的刚度进行了精确计算,得到其在不同载荷作用下刚度的精确解,并讨论了弹性铰链的刚度随椭圆长短轴之比变化时的情况。当椭圆的长短轴之比由1变化到无穷大时,即由圆形凹槽经过椭圆凹槽变化到矩形凹槽时,弹性铰链的刚度逐渐减小,由此引起的应力集中也逐渐减小,但是运动精度也随之降低。利用有限元方法对弹性铰链的刚度和运动精度进行了校验。     

Influences of Randomly Distributed Wall THickness of Beverage Can on Its Strength and Stiffness

This paper describes the research undertaken on the strength and stiffness of fluctuation on the wall thickness of steel beverage cans using the Monte-Carlo stochastic finite element method.Sample distributions were firestly assumed and then proven using the data observations of the wall thickness.the APDL language was then applied,and the stresses and displacements of the can were calculated by using the ANSYS software.It is concluded that the structureal reliability of a steel-making beverage can be estimated accurately.     

Bearing Capacity of Mixed Pile with Stiffness Core

To study load transfer mechanism and bearing capacity of a mixed pile with stiffness core (MPSC), which is formed by inserting a precast reinforced concrete pile (PRCP), in-situ tests involving MPSCs with different lengths, diameters, water cement ratios and PRCPs, cement mixed piles, and drilling hole piles, were carried out. Limit bearing capacities, load-settlement curves and stress distribution of MPSCs and mixed piles were obtained. The load transfer between cement soil and PRCP was analyzed by finite element method (FEM). Test results and FEM analysis show that an MPSC has fully utilized the big friction from a cement mixed pile and the high compressive strength from a PRCP which transfers outer top load into the inner cement soil, and that inserting a PRCP into a mixed pile changes the stress distribution of a mixed pile and improves frictional resistance between a mixed pile and soil. The length and the section area on PRCP of an MPSC both have an optimum value. Adopting MPSC is effective in improving the bearing capacity of soft soil ground.     

钢筋砼结构施工期楼层承载力的安全性复核

提出多层钢筋砼结构在施工期间,施工荷载在各相关楼层间的分配及承载力安全性复核的方法。解决了多层砼结构模板支撑系统的安装及拆除无依据、凭经验施工的问题。     

受周期力作用刚度不均等转轴的副临界转速

有关转轴临界转速,迄今已有不少讨论,本文就刚度不均等转轴,提供一种临界转速的分析计算方法。