薄板结构边界支承刚度的识别

Boundary Stiffness Identification of a Thin Plate Structure

本文用动态测试与边界元法数值计算相结合的方法来识别薄板结构的边界支承的刚度参数。薄板在给定的激励下,根据在薄板有限点上振动响应的测量值,利用结构边界积分方程的解析关系即可较准确地估算出边界支承的参数。在建立边界积分方程中,采用了近似基本解技术。通过算例,验证了方法的可行性和有效性,其识别精度对工程问题来说,是足够满意的。

In the paper,an approach linking dynamic measurement and BEM is proposed to identify the bound-ary rotating stiffness of a thin plate structure.Making use of BEM and according to the boundary integralequation,the relation between the dynamic response at any point of the structure and the boundary param-eters can be established.Under certain excitation,the vibration responses at some points of the plate aremeasured and processed to identify the boundary parameters and then to determine the elastic suppportstiffness of the plate.In deriving the boundary integral equation,the difficulty lies in finding a functionalformed fundamental solution for structural dynamic problems.In this paper,an approximate fundamentalsolution is adopted instead,which is composed of a fundamental solution for a corresponding static prob-lem and a series term for correction.A simulation example is presented to verify the effectiveness of themethod offered.In the example,a rectangular plate with one edge elastically supported is examined.Un-der harmonic excitation,with three measuring points on the plate and with four diveded boundary ele-ments,satisfactory identification result of the plate support stiffness is obtained.Its accuracy is sufficient-ly high for engineering use.Principally,this approach can no doubt be extended to the boundary conditionidentification of more complicated structures,such as shells,three dimensional bodies and so on.