静载荷作用下柔韧圆板的大幅度振动

本文首先给出了均布载荷作用下柔韧圆板的大幅度振动方程，按文中给出的时间模态假设导了该问题的非线性耦合的代数和微分特征方程组，利用修正迭代法求出了该方程组的近似解析解，得到了柔韧圆振动的幅频－载荷特征关系，讨论了静载荷对其振动性态的影响。     

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.     

正交各向异性压磁电弹性矩形板的稳定问题

从压磁电弹性力学的三维平衡方程和本构关系出发,推导得到了正交各向异性压磁电弹性矩形板稳定问题的状态方程。求解状态方程并结合边界条件得到了稳定问题的屈曲方程。给出了临界应力的算例。     

割口单向叠层板的拉伸应力集中与强度

基于剪滞理论,建立一种分层剪滞模型,分析了含割口的单向叠层板在拉伸载荷作用下的应力重新分布问题,获得了割口前缘完整纤维的应力集中因子.在此基础上,采用细观统计破坏理论,研究了割口单向叠层板的拉伸破坏强度,得到了与现有实验较吻合的结果.     

粘弹性基支粘弹板轴对称问题的动力响应

本文讨论粘弹性半空间地基上粘弹性圆板受轴对称载荷时的动力响应,将问题化为在Laplace变换空间中的第一类Fr积分方程,通过数值解和进行数值逆变换求得问题的解答。     

NONLINEAR VIBRATION OF CIRCULAR SANDWICH PLATES UNDER CIRCUMJACENT LOAD

Based on von Karman plate theory, the issue about nonlinear vibration for circular sandwich plates under circumjacent load with the loosely clamped boundary condition was researched. Nonlinear differential eigenvalue equations and boundary conditions of the problem were formulated by variational method and then their exact static solution can be got. The solution was derived by modified iteration method, so the analytic relations between amplitude and nonlinear oscillating frequency for circular sandwich plates were obtained. When circumjacent load makes the lowest natural frequency zero, critical load is obtained.     

圆板承受一般轴对称分布载荷的解析计算方法

 运用泰勒级数方法, 可计算圆板和圆环形板承受 不光滑, 不连续轴对称分布载荷的问题.     

Modeling the interaction of solitary waves and semi-circular breakwaters by using unsteady reynolds equations

A vertical 2 -D numerical wave model was developed based on unsteady Reynolds equations. In this model, the k-epsilon models were used to close the Reynolds equations, and volume of fluid( VOF) method was used to reconstruct the free surface. The model was verified by experimental data. Then the model was used to simulate solitary wave interaction with submerged, alternative submerged and emerged semi-circular breakwaters. The process of velocity field, pressure field and the wave surface near the breakwaters was obtained. It is found that when the semi-circular breakwater is submerged, a large vortex will be generated at the bottom of the lee side wall of the breakwater ; when the still water depth is equal to the radius of the semi-circular breakwater, a pair of large vortices will be generated near the shoreward wall of the semi-circular breakwater due to wave impacting, but the velocity near the bottom of the lee side wall of the breakwater is always relatively small. When the semi-circular breakwater is emerged, and solitary wave cannot overtop it, the solitary wave surface will run up and down secondarily during reflecting from the breakwater. It can be further used to estate the diffusing and transportation of the contamination and transportation of suspended sediment.     

有初内力的板的内共振

本文利用非线性时空有限方法和样条有限元技术对具有初内力的板的非线性频响特性进行了分析，计算了在不同初始内力下方板的大振幅自由振动、有阻尼强迫振动和矩形板的内共振。