中文摘要：

梁结构在工程设计中有着广泛应用,其支承情况多种多样,往往不能简单地按理想的固支或简支梁来处理.以一种混合边界条件下短梁结构为研究对象,进行了短梁的模态试验,并基于Abaqus有限元软件,分别对端面固定边界约束、一端固定边界约束、弹性＋固定边界混合约束条件下短梁结构进行模态分析.结果表明,边界约束条件通过改变系统刚度,导致模态特征改变.不同边界条件下的梁结构约束模态特征具有显著差异.采用混合边界条件的梁结构约束模态频率与试验结果吻合.

英文摘要：

Beam structure is widely employed in engineering applications. Its supporting conditions can not be easily dealt with as ideal fixed or simply supported ones in practice. The dynamics of a short beam under hybrid-boundary conditions was served as the study object. Modal analyses of short beam structure under different boundary conditions were performed by utilizing the finite element analysis software of Abaqus. Results show that the boundary condition can change the system stiffness, and alter the structure modal characteristics. The modals of short beam vary from the boundary conditions. The analyzed modal frequencies of short beam under mixed bound- ary conditions consist well with the modal experiment results.