New mixed plate-bending elements with shear strain interpolations

This paper is concerned with two mixed plate-bending elements with shear strain interpolations, a quadrilateral element and an 8-node serendipity-type element based on discussions on the element proposed in Ref.[1]. The shear strains and inner-forces in the natural coordinates are interpolated in an element and then transformed into Cartesian coordinates in accordance with covariant and contravariant tensor transformations, respectively. The quadrilateral element coincides with the element in Ref.[1] when it is rectangular. Numerical examples show that the two new elements are free from shear locking and spurious kinematic modes under regular and irregular meshes and have the advantages of being insensitive to element distortion and able to give fairly accurate results.The Project supported by National Natural Science Foundation of China.     

复合消色差补偿器

给出一种新的三元复合式消色差补偿器，该补偿器具有调节方便、精度高、在一定波长范围内消色差性能良好等优点。     

THE METHOD OF THE RECIPROCAL THEOREM OF FORCED VIBRATION FOR THE ELASTIC THIN RECTANGULAR PLATES(Ⅱ)—RECTANGULAR PLATES WITH TWO ADJACENT CLAMPED EDGES

In this paper,applying the method of reciprocal theorem,we give the distributions ofthe amplitude of bending moments along clamped edges and the amplitude of deflectionsalong free edges of rectangular plates with two adjacent clamped edges under harmonicdistributed and concentrated loads.     

Scanning electrochemical microscopy (SECM) of nanolitre droplets using an integrated working/reference electrode assembly

Scanning electrochemical microscopy (SECM) has been performed in the restricted space of nanolitre droplets with a robust and easy-to-handle coaxial electrode assembly centring a Pt microdisk in a circular Ag electrode. Straightforward and reproducible fabrication of the specially designed probe tips was achieved by using Tollens reaction to chemically deposit a uniform and well-adhering layer of silver on the body of a glass-insulated Pt microdisk electrode. The suitability of the novel dual-electrode SECM tip for measurement in small volumes was evaluated by imaging an array of four Pt band microelectrodes in 500 nL electrolyte.     

Determination of the parameters of a three-dimensional heat release region in a supersonic stream from pressure measurements

Three-dimensional steady-state supersonic flow with weak heat release is analyzed. Two conjugate problems are considered: determination of the forces exerted on surfaces surrounding a given heat source and determination of the release region and the amount of heat released from pressure measurements in the surrounding space. Features of the three-dimensional flow are found. The characteristic properties of the three-dimensional flow are illustrated with reference to a spherical Gaussian source.     

Comments on Reply to Comments on “Non-Darcian Forced Convection Flow of Viscous Dissipating Fluid Over a Flat Plate Embedded in a Porous Medium”

This note is a comment on the reply by Aydin and Kaya (Transp Porous Media (to appear), 2008b) to comments by Rees and Magyari (Transp Porous Media (to appear), 2008) on an article by Aydin and Kaya (Transp Porous Media (to appear), 2008a) concerning the combined effects of viscous dissipation and surface mass flux on the forced convection boundary-layer flow in a saturated porous medium modeled by the Brinkman equation. It is argued that the statements by Rees and Magyari are in fact appropriate. The thermal boundary condition imposed at the edge of the boundary-layer by Aydin and Kaya is incompatible with the energy equation, and thus the results of their paper are inconsistent with the physics of the situation. The attempts of Aydin and Kaya to justify their paper are flawed by an inappropriate assumption and calculations with an insufficiently large parameter.     

5级人防口部粘钢封堵接头抗爆实验研究

通过粘钢实现一典型汽车库人防口部封堵的设计方案,并对原设计方案进行相似设计后,对粘钢接头结构实验模型在核爆炸压力模拟器中进行模爆实验,得到沿竖向支座钢板的位移和应变时程曲线,并和有限元数值解进行了对比,其结果均较吻合,通过沿竖向支座钢板的应变分布规律得到钢板-混凝土界面之间的粘结应力;检验了在5级人防爆炸冲击波作用下,混凝土墙与钢板间粘结面承载力的可靠性;分析了5级人防爆炸荷载作用下支座钢板沿竖向应力的分布规律,为确定混凝土墙与钢板之间粘结应力的计算方法提供了参考。     

微孔洞唯象损伤力学模型及其应用

基于微损伤发展的NAG(nucleation and growth)模型,从唯相角度,得到了一种微孔洞损伤演化方程。在考虑损伤软化和温度软化的基础上得到了材料含损伤本构关系。将损伤演化方程和材料本构关系引入ABAQUS有限元软件对D6AC和921两种钢板撞击层裂问题进行数值模拟。模拟结果与实验结果吻合。     

Viscoplastic deformation of reinforced plates with varying thickness under explosive loads

The problem of viscoplastic bending of reinforced plates with varying thickness is formulated. An original method for the integration of this initial-boundary-value problem is developed. The numerical solution is compared with an analytical solution obtained with a rigid-plastic model of an isotropic circular plate. The efficiency of the method is demonstrated by analyzing the inelastic dynamics of reinforced plates with constant and varying thickness. It is shown that the maximum residual deflections of plates can be reduced severalfold by means of rational profiling and reinforcement __________ Translated from Prikladnaya Mekhanika, Vol. 44, No. 2, pp. 85–98, February 2008.