叠层复合材料圆柱壳的细-宏观阻尼特性预测

研究了叠层复合材料圆柱壳的细-宏观阻尼特性。基于Reissner-Naghdi薄壳理论,给出了圆柱壳的振动微分方程,在分量变量的过程中,采用Haar小波级数表示轴向振型,Fourier级数表示环向振型,通过边界条件求解积分过程中出现的未知系数,进而得到用于分析圆柱壳自由振动特性的特征方程;基于单层混杂材料的细观力学阻尼计算方法和多胞模型,分别获得单层复合材料的等效阻尼特性和等效弹性特性,利用复模量法对复合材料圆柱壳的阻尼特性进行预测。通过与其他文献中阻尼预测的结果进行对比,验证了该研究所采用方法的有效性;进一步针对四种典型的边界条件,即固支-固支(C-C)、固支-简支(C-S)、简支-简支(S-S)、固支-自由(C-F)等边界,从细-宏观层面分析了纤维含量、环向波数、铺层方式和几何参数等因素对复合材料圆柱壳阻尼特性的影响规律。

Prediction of micro-macro damping characteristics of laminated composite cylindrical shells

Micro-macro damping characteristics of laminated composite cylindrical shells were studied here.Based on Reissner-Naghdi thin shell theory,the vibration differential equations of a cylindrical shell were derived.In process of separation of variables,Haar wavelet series was used to represent axial mode,and Fourier series was used to represent circumferential mode.The unknown coefficients appearing in integration were solved using boundary conditions to obtain the characteristic equation to be used for analyzing free vibration characteristics of the cylindrical shell.Based on the microscopic damping calculation method and multi-cell model of hybrid materials,the equivalent damping characteristics and equivalent elastic characteristics of single-layer composite material were obtained,and damping characteristics of a composite cylindrical shell were predicted using the complex modulus method.By comparing damping prediction results with those published in other literature,the effectiveness of the proposed method was verified.Effects of fiber content,circumferential wave number,laminated mode and geometric parameters on damping characteristics of composite cylindrical shell under four typical boundary conditions were further analyzed.