关于结构限制失稳的研究进展

限制失稳是指构件失稳时其屈曲变形不能自由发展而受到某种限制性约束的失稳,有时又称单向失稳、接触失稳、约束失稳.这类问题在工业中有大量应用,也是固体力学中的一个经典问题.最常见的实例如应用于地下管道、隧道、压力容器、核反应堆安全壳中的薄衬壳,当薄衬壳发生屈曲时,由于受到外壁的约束,其屈曲行为和一般的壳体屈曲行为不同,这就需要我们发展新的研究方法.另外如受钻井套管横向约束的钻柱的屈曲,复合材料的分层屈曲,电子元器件中的镀层屈曲等也属于限制失稳的范畴.限制失稳问题因其涉及接触问题、单向屈曲、非保守问题等而显得十分复杂,一直没有得到很好的解决.从近年来文献看,限制失稳的研究多集中在压杆、圆环的研究,板、壳的研究相对较少.本文首先简单介绍了限制失稳的一般概念,指出存在的限制约束对结构屈曲特性的影响.然后分别介绍了对于杆、环、板、壳的 受限制失稳的研究进展.最后提出了需要进一步深入研究的问题.图11参75

SOME ADVANCES IN CONFINED BUCKLING

Confined buckling, which is also called unilateral buckling, one-way buckling, contact buckling, or constrained buckling, means that the buckling configuration of structures can not be evolved freely due to the presence the external obstacles. This type of problems has many applications in industry. It is also a classic problem of solid mechanics. The most familiar examples are thin liners in the underground pipings, tunnels, pressure containers and reactor containments. When a thin liner buckles, the modes of buckling are different from those of general shells because of the constraint of the outside wall. Some new research methods should be developed. Some other examples include the buckling of pipes in oil industry, delamination of composite materials, buckling of plating layer in electronic elements and so on. The problem is complex and not well solved yet, because it involves non-linearity, such as contact, one-way buckling and non-conservation etc. In recent years, more attention has been paid on confined buckling of bars and rings. The research of plates and shells is not enough. In this paper, the general concept of the confined buckling is introduced. The influence of the external obstacle on the characteristics of buckling of structures is discussed. Some advances in the confined buckling of bars, rings, plates and shells are reviewed. Finally several important problems that need to be researched further are pointed out.