高温下含多条裂纹简支钢梁的模态分析
发布时间：2018-11-17 11:38
【摘要】：基于传递矩阵方法,提出了一种在高温下对含多条裂纹简支钢梁进行模态分析的方法。在模态分析过程中,用无质量的扭转弹簧来等效横向裂纹,推导出每条裂纹产生的局部柔度;通过材料力学参数的变化引入温度模块,考虑温度变化在简支梁截面产生的轴向载荷的影响,推导出含温度参数、裂纹条数和裂纹几何参数的整条裂纹梁传递矩阵。根据简支梁的边界条件,求解出不同温度下含多条裂纹简支钢梁的固有频率。结果表明:简支梁横截面上的轴向温度载荷对固有频率的影响非常大,不能忽略不计;温度的升高会显著减小裂纹简支钢梁的各阶固有频率;随着裂纹相对深度的增大,裂纹简支钢梁第一阶固有频率和临界温度均逐渐降低。
[Abstract]:Based on the transfer matrix method, a modal analysis method for simply supported steel beams with multiple cracks at high temperature is proposed. In the process of modal analysis, a massless torsional spring is used to equivalent the transverse crack, and the local flexibility of each crack is derived. By introducing the temperature module into the material mechanics parameters and considering the influence of temperature change on the axial load of the simply supported beam, the transfer matrix of the whole cracked beam with temperature parameters, crack number and crack geometry parameters is derived. According to the boundary conditions of simply supported beams, the natural frequencies of simply supported steel beams with multiple cracks at different temperatures are calculated. The results show that the axial temperature load on the cross section of simply supported beam has a great influence on the natural frequency and can not be ignored, and the increase of temperature can significantly reduce the natural frequencies of simply supported steel beams with cracks. With the increase of the relative depth of cracks, the first natural frequency and critical temperature of simply supported steel beams with cracks decrease gradually.
【作者单位】： 南京航空航天大学机械结构力学及控制国家重点实验室;
【基金】：江苏高校优势学科建设工程基金(PAPD)
【分类号】：TG142.1
，
本文编号：2337647
[Abstract]:Based on the transfer matrix method, a modal analysis method for simply supported steel beams with multiple cracks at high temperature is proposed. In the process of modal analysis, a massless torsional spring is used to equivalent the transverse crack, and the local flexibility of each crack is derived. By introducing the temperature module into the material mechanics parameters and considering the influence of temperature change on the axial load of the simply supported beam, the transfer matrix of the whole cracked beam with temperature parameters, crack number and crack geometry parameters is derived. According to the boundary conditions of simply supported beams, the natural frequencies of simply supported steel beams with multiple cracks at different temperatures are calculated. The results show that the axial temperature load on the cross section of simply supported beam has a great influence on the natural frequency and can not be ignored, and the increase of temperature can significantly reduce the natural frequencies of simply supported steel beams with cracks. With the increase of the relative depth of cracks, the first natural frequency and critical temperature of simply supported steel beams with cracks decrease gradually.
【作者单位】： 南京航空航天大学机械结构力学及控制国家重点实验室;
【基金】：江苏高校优势学科建设工程基金(PAPD)
【分类号】：TG142.1
，
本文编号：2337647
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