材料物性热效应对统计能量分析参数的影响

摘要

Environment temperature changes material property and then affects statistical energy analysis (SEA) parameters.It is necessary to study the effect of temperature-dependent material property on SEA parameters before establishing a SEA model with considering temperature.Firstly,the model of an L-shaped plate was created,which was simple supported at all sides.Secondly,the rain-on-the-roof load was applied on one plate of the L-shaped plate,and the frequency-averaged input power of load as well as the vibration energy of each sub-system at different temperatures corresponding to different mode sets was obtained based on the energy flow models.The effect of temperature-dependent material property was considered.Finally,the damping loss coefficient and coupling loss coefficient were defined by the product of the central frequency and the damping loss factor/coupling loss factor,respectively,based on the power injection method.Results show that the global modal density and the frequency-averaged input power of the rain-on-the-roof load are changing with the temperature and they have the contrary trend with the elastic modulus of the L-shaped plate verse temperature;the damping loss coefficients and coupling loss coefficients are changing with the temperature and they have the same trend with the elastic modulus of the L-shaped plate verse temperature.%高温环境会引起系统的统计能量分析参数发生变化，原因之一是温度改变了材料物性。为建立计及材料物性热效应的统计能量分析模型，有必要先研究材料物性热效应对统计能量分析参数的影响。针对四周简支的 L 形折板结构，在一板上施加雨流载荷（rain-on-the-roof），计及材料物性热效应，基于能量流模型分析得到子结构不同温度下对应于特定模态群的载荷的平均输入功率及各子系统的平均振动能量，再基于 PIM理论分析得到由内损耗因子、耦合损耗因子与频带中心频率的乘积定义的参数：内损耗系数、耦合损耗系数。研究结果表明：整体模态密度、雨流载荷的平均输入功率与板材面内弹模随温度的变化趋势相反；内损耗系数、耦合损耗系数与板材面内弹模随温度的变化趋势相同。