用边界元法计算结构振动辐射声场

讨论了用边界元法计算结构振动辐射声场的数值方法。对计算中的积分奇异性采用三角形斜坐标系、退化单元法进行处理，构造了三角形、四边形线性等参元和四边形二次等参元。对特征频率处解不惟一问题采用ＣＨＩＥＦ加Ｌａｇｒａｎｇｅ乘子法进行处理。构造单元具有简单、规范和精确等优点，可用来计算已知表面振速结构的声辐射，或与相应的结构有限元结合，计算结构的振动辐射声场。以脉动球和辐射立主体为例，计算了结构表面声压、声

Calculation of acoustic field radiated by vibrating structures using BEM

The determination of the acoustic field radiated by a vibrating structure using BEM is discussed. The skew triangle coordinate and the degenerative elements are used to overcome the singular integrals and the isoparametric elements of linear triangular and quadrilateral elements and quadratic quadrilateral elements are constructed. The CHIEF plus the Lagrange multiplier is employed to solve the non uniqueness problems. The elements presented in this paper to calculate acoustic radiation of structures with prescribed surface velocity distribution or structural vibration and acoustic radiation with corresponding structural finite elements are simple, normalized and accurate. Numerical examples of calculating the surface pressure, farfield pressure, radiated power and radiation efficiency of spherical and cubical radiation are given and compared with analytical solution and the property and accuracy of the constructed elements are discussed too.