Research On Computing Methods With High Efficiency And Precision For Acoustic Meta-materials Of Automobile Vibration-control

Meta-materials have the character of banning or controlling the spreading of elastic waves in aiming range,which provides a new research direction of improving automobile vibration-control character for us.Finite element method(FEM)is widely used in meta-materials research of the mechanism of bandgap,energy band structure and influence factors to enhance the work efficiency.However,traditional FEM has a problem that its numerical model is stiffer than real model,which causes wave length in calculating higher than real value.Therefore,this article do the following work based on triangle element and quadrated element when analyzing 2D meta-materials bandgap:1.build up smooth region based on triangle element,and stiffness matrix strain gradient to reduce calculation error;on the other hand,analyze gauss point of mass matrix,and then rebuild new mass matrix to match smooth strain gradient,to reduce calculation error further.2.build up smooth region based on quadrated element,and stiffness matrix strain gradient to reduce calculation error;on the other hand,analyze gauss point of mass matrix,and then rebuild new mass matrix to match smooth strain gradient,to reduce calculation error further.And then use local resonance acoustic meta-materials and bragg meta-materials as numerical example to calculate bandgap,radios in high frequency,relative error rate,and convergence rate in different size of element.The results show that when using triangle element modified edge smooth finite element method with mass matrix reconstruction calculation accuracy and convergence rate is higher than other finite element methods;when using quadrilateral element partition smooth finite element method of Lump mass matrix accuracy and convergence rate is higher than other finite element methods.Furthermore,this article is aiming at solving the problem of broadband in200-300 Hz of a type automobile by using triangle element modified edge smooth finite element method with mass matrix reconstruction,and which is proved to be consistent with that done by the quadrilateral element partition smooth finite element method of Lump mass matrix.