热/机械载荷下功能梯度材料矩形厚板的弯曲行为

采用Reddy高阶剪切板理论,考虑材料物性参数随坐标和温度变化的特性,研究在均匀变化的温度场内功能梯度材料矩形板在面内与横向载荷共同作用下的横向弯曲问题,基于一维DQ法和Galerkin技术,给出了一对边固支、另对边任意约束时板弯曲问题的半解析解.以Si3N4/SUS304板为例考察了材料组份、温度场、面内载荷及边界约束条件等对功能梯度材料板弯曲行为的影响.     

颗粒增强复合材料的椭圆形刚性夹杂呈双周期分布模型的反平面问题研究

在遵循复合材料中各夹杂相互影响的重要条件下,构造呈双周期分布且相互影响的椭圆形刚性夹杂模型的复应力函数,采用坐标变换和复变函数的依次保角映射方法,达到满足各个夹杂的边界条件,利用围线积分将求解方程化为线性代数方程,推导出了在无穷远双向均匀剪切,椭圆形刚性夹杂呈双周期分布的界面应力解析表达式,最后的算例分析给出了夹杂的形状对界面应力最大值(应力集中系数)的影响规律,并描绘出了曲线.     

胶补加筋板应力强度因子及胶层剪应力计算

在铆钉力法的基础上，提出计算胶接修补加筋板结构应力强度因子及胶层剪应力的解析法，对分析胶接修补的加筋板强度具有现实意义．利用影响系数，可以得到筋条、补片及蒙皮位移的表达式，根据位移协调条件，建立联立方程，从而得到胶层剪应力及铆钉力．通过解析式，计算裂纹尖端的应力强度因子，分析补片对结构修补的效果，综合考虑了筋条及补片对应力强度因子的影响．     

血流动力学与动脉粥样硬化

动脉粥样硬化引发的心血管疾病已成为疾病死亡的主要原因，动脉粥样硬化虽是一多因素疾病，但该疾病的局部性现象却与心血管系统的血流动力学特性有关。目前，人们在这一领域的研究重点主要集中于弄明局部应力，特别是流动剪切应力变化对动脉血管生理和病理的影响，本在综述血流动力学因素对动脉粥样硬化的影响的同时，根据实验研究提出了一些新的见解，认为血管内壁脂质浓度极化也是造成动脉粥样硬化的重要因素。     

多功能Hopkinson压杆型试验装置的研制与应用

对传统的Hopkinson压杆试验装置进行了改进和完善，除了用于材料的动态压缩以外，还能进行动态拉伸、绝热剪切、裂纹扩展速度测定、动态断裂韧性测试等．本文介绍了几种试验方法的基本原理，并给出了试验结果．     

一种考虑剪切变形的平行四边形厚/薄板通用单元

根据Timoshenko二广义位移梁理论，构造了深梁位移场的插值函数。利用斜坐标系与直角坐标系的变换关系、有限条带思想和深梁位移插值函数，构造了一种考虑剪切变形的平行四边形厚／薄板弯曲通用单元的位移(曲率、剪应变、转角、横向位移)插值函数，导出了刚度矩阵和非结点荷载等效力。并对简支阍支方板、Razzaque斜板、四边简支斜交板弯曲进行了数值计算。算例表明此单元有较好的精度，对于薄板不出现剪切闭锁，可适应于目前桥梁建设中大量采用的斜交板桥结构分析。     

On the interaction between a dislocation and a circular inhomogeneity with imperfect interface in antiplane shear

The solution of appropriate elasticity problems involving the interaction between inclusions and dislocations plays a fundamental role in many practical and theoretical applications, namely, it increases the understanding of material defects thereby providing valuable insight into the mechanical behavior of composite materials.Although the problem of a three-phase circular inclusion interacting with a dislocation in antiplane shear has been presented [Xiao and Chen, Mech. Mater. 32 (2000) 485], the analysis is limited to the classical perfect bonding condition. The current paper considers the solution for a homogeneous circular inclusion interacting with a dislocation under thermal loadings in antiplane shear. The bonding along the inhomogeneity–matrix interface is considered to be imperfect with the assumption that the interface imperfections are constant. It is found that when the inhomogeneity is soft, regardless of the level of interface imperfection, the inhomogeneity will always attract the dislocation. As a result, no equilibrium positions are available. Alternatively, when the inhomogeneity is hard, an unstable equilibrium position is found which depends on the imperfect interface condition and the shear moduli ratio μ₂/μ₁.     

冲击载荷下剪切断裂研究

利用Hopkinson压杆技术对单边平行双裂纹试样倒向加载，在较大的加载率范围，对Ti6Al4V钛合金和40CrNiMoA两种材料的动态剪切断裂行为进行了研究．实验结果表明：存在两类韧性剪切断裂模式，即常规的韧性剪切型断裂和绝热剪切断裂．常规剪切型断裂模式的断裂韧性KⅡd随加载率的提高而增大，而绝热剪切型的断裂韧性KⅡd则随加载率的提高而减小，并且，当加载率增大至某一临界值时，常规的韧性剪切断裂模式将转变为绝热剪切断裂破坏模式．     

带旋转自由度C^0类任意四边形板（壳）单元

基于Ｒｅｉｓｓｎｅｒ－Ｍｉｎｄｉｌｉｎ板弯曲理论和Ｖｏｎ－Ｋａｒｍａｎ大挠度理论,采用单元域内和边界位移插值一致性的概念,将四节点等参弯曲单元与Ａｌｌｍａｎ膜变形二次插值模式相结合,对层合板壳的大挠度分析提供了一种实用的带旋转自由度的四节点Ｃ＾０类板单元。大量算例表明：该单元对板壳结构的线性强度、稳定性和后屈曲分析都表现出良好的收敛性和足够的工程精度。     

SHEAR BEAM MODEL FOR INTERFACE FAILURE UNDER ANTIPLANE SHEAR (Ⅰ)—FUNDAMENTAL BEHAVIOR

The propagation of interlayer cracks and the resulting failure of the interface is a typical mode occurring in rock engineering and masonry structure. On the basis of the theory of elasto~plasticity and fracture mechanics, the shear beam model for the solution of interface failure was presented. The concept of `cohesive crack’ was adopted to describe the constitutive behavior of the cohesive interfacial layer. Related fundamental equations such as equilibrium equation, constitutive equations were presented. The behavior of a double shear beam bonded through cohesive layer was analytically calculated. The stable propagation of interface crack and process zone was investigated.