不同边界条件正交各向异性中厚板的振动与稳定分析

本文采用高阶剪切变形理论对正交各向异性中厚矩形板进行振动与稳定分析,数值计算采用样条有限点法,得出了六种不同边界条件矩形板的自振频率和屈曲载荷,并与相应的经典板理论的结果进行比较.结果说明横向剪切变形对复合材料层合板的影响与板的各向异性程度、板的宽厚比(b/h)、层合板的层数和板的支承条件有关,它随着层合板各向异性程度的增加而增加,随着层合板宽厚比的增加而逐渐消失.     

ANALYTICAL EVALUATION OF PERMANENT DEFLECTION OF A THIN CIRCULAR PLATE STRUCK NORMALLY AT ITS CENTER BY A PROJECTILE

The permanent deflection of a thin circular plate struck normally at its center by a projectile is studied by an approximate theoretical analysis,FEM simulation and experiment.The plate made of rate sensitive and strain-hardening material undergoes serious local deformation but is not perforated during the impact.The theoretical analysis is based on an energy approach, in which the Cowper-Symonds equation is used for the consideration of strain rate sensitive effects and the parameters involved are determined with the aid of experimental data.The maximum permanent deflections predicted by the theoretical model are compared with those of FEM sim- ulation and published papers obtained both by theory and experiment,and good agreement is achieved for a wide range of thickness of the plates and initial impact velocities.     

ANALYSIS ON THE MAGNETO-ELASTIC-PLASTIC BUCKLING/SNAPPING OF CANTILEVER RECTANGULAR FERROMAGNETIC PLATES

An analysis of buckling/snapping and bending behaviors of magneto-elastic-plastic interaction and coupling for cantilever rectangular soft ferromagnetic plates is presented.Based on the expression of magnetic force from the variational principle of ferromagnetic plates,the buckling and bending theory of thin plates,the Mises yield criterion and the increment theory for plastic deformation,we establish a numerical code to quantitatively simulate the behaviors of the nonlinearly multi-fields coupling problems by the finite element method.Along with the phenom- ena of buckling/snapping and bending,or the characteristic curve of deflection versus magnitude of applied magnetic fields being numerically displayed,the critical loads of buckling/snapping, and the influences of plastic deformation and the width of plate on these critical loads,the plastic regions expanding with the magnitude of applied magnetic field,as well as the evolvement of deflection configuration of the plate are numerically obtained in a case study.     

一种材料力学CAI辅学课件的研制

介绍一种材料力学ＣＡＩ训练型课件的功能和特点，课件的开发旨在为改进材料力学的教学方法作些尝试．     

集中力作用下简支梁弯曲强度研究

本文研究了简支梁在各种情况集中力作用下的弯曲强度，指出了目前材料力学教材中“把较大的集中力分散成较小的力”作为提高弯曲强度措施的不全面之处．     

弹-粘塑性梁的弯曲

给出矩形截面弹 粘塑性梁弯曲问题的求解方程，指出求解该方程的困难     

复杂梁动力问题的近似分析方法

本文介绍了在各种复杂条件下，分析梁振动特性的一个近似方法－模态摄动法。这一方法是在等截面均匀梁的模态子空间内实施，将复杂梁的变系数微分方程的求解转化为代数方程组的求解。通过算例，表明这一方法简单实用，且有良好的近似性。     

Reisner板的哈密尔顿体系及其辛正交解析法

基于Ｒｅｉｓｎｅｒ板理论，通过对混合能变分原理的修正，建立了更一般的哈密尔顿型广义变分原理，并给出了Ｒｅｉｓｎｅｒ板问题的哈密尔顿正则方程及其共轭辛正交解析法     

一个厚薄板通用的三角形板弯元

本文提出了一个新的厚薄板通用的三角形板弯元,根据Hellinger-Reissner变分原理推导出来的新单元具有独立的转角、位移、剪应变和弯曲应变的插入函数,它没有其它混合元所存在的一些缺点。一些典型例子表明这个新单元具有很好的特性,刚度矩阵简单,计算精度高,收敛速度快以及厚薄板通用性强。     

杂交梁界面剪应力的理论分析和数值模拟

采用解析和数值方法研究FRP-混凝土杂交梁的界面应力问题。提出了杂交梁的新的力学模型和假设,克服了以往的分析模型中界面应力表达式非常复杂和界面应力的解析解与数值解相差较大的缺点,本文得到的FRP板加固梁的界面剪应力表达式与数值结果符合很好,并且具有简捷的表达式。利用有限元法研究了杂交梁各物理参数对界面剪应力的影响。研究表明,界面剪应力在FRP板的端部存在应力集中或应力奇性,这是造成杂交梁界面破坏的主要原因。这项研究对进行杂交结构的工程设计具有理论指导和参考价值。