The present research focuses on performing the dynamic study of a cracked, internally damped, composite rotating shaft system with journal bearing end supports. A novel mathematical formulation is proposed to introduce a time-varying stiffness matrix for simulating the breathing behaviour of the crack. The random search algorithm is used as one of the metaheuristic processes to carry out the optimization and generate time-dependent geometric parameters of the cracked surface for one full rotation. The derived stiffness matrix is used in the composite shaft’s higher order motion equation obtained through equivalent modulus theory, whose internal damping properties are incorporated using operator-based viscoelastic model. Eigenanalysis is carried out to perform a thorough study of dynamic characteristics of cracked shaft considering the crack depth and crack position as two important parameters. The effect of crack on stacking sequence as well as mode shapes of the heterogeneous laminated shaft is also studied.

目前的研究重点是对带有轴颈轴承端部支撑的裂纹、内部阻尼复合旋转轴系统进行动态研究。提出了一种新的数学公式来引入时变刚度矩阵来模拟裂纹的呼吸行为。随机搜索算法被用作元启发式过程之一，以进行优化并生成完整旋转一圈的裂纹表面的时间相关几何参数。推导出的刚度矩阵用于通过等效模量理论获得的复合轴的高阶运动方程，其内部阻尼特性使用基于算子的粘弹性模型合并。考虑裂纹深度和裂纹位置作为两个重要参数，进行特征分析以对裂纹轴的动态特性进行深入研究。还研究了裂纹对异质叠层轴的叠层顺序和模态振型的影响。