基于模态叠加法的面压载荷与基础激励等效方法

发布时间：2018-08-19 11:54

【摘要】：基于模态叠加法,将随机面压载荷等效为随机基础激励,为薄壁构件的振动台试验替代成本较高的噪声试验提供依据.该方法要求等效前后2种载荷作用下主模态位移一致,将单源载荷等效这一超静定问题合理简化为静定问题.以炭/炭复合材料悬臂板为研究对象,来验证载荷等效方法的有效性.分析结果显示,在随机面压载荷及等效随机基础激励作用下,板上典型部位随机正应力响应的功率谱密度高度吻合,在分析频段内危险点处x轴向正应力响应均方根分析误差低于1%,分布在板上的5个响应点处x轴向正应力响应均方根分析误差低于2%.该方法能有效地将随机面压载荷等效为基础激励,保证等效前后2种载荷作用下薄壁构件的随机动应力响应在频域及空间域上的分布一致性.
[Abstract]:Based on the modal superposition method, the random surface compression load is equivalent to the random foundation excitation, which provides the basis for replacing the high-cost noise test with the shaking table test of thin-walled members. In this method, the displacement of the main mode should be the same under the two kinds of loads, and the statically indeterminate problem of the equivalent load of a single source should be reasonably simplified as a statically indeterminate problem. The cantilever plate of carbon / carbon composites was studied to verify the effectiveness of the load equivalent method. The results show that the power spectral density of the random normal stress response of typical parts of the plate is in good agreement with the equivalent random foundation excitation under the random surface compression load. The root mean square error of x axial normal stress response is less than 1 at the risk point in the analysis band, and less than 2% at 5 response points distributed on the plate. This method can effectively equalize the random surface compressive load as the basic excitation, and ensure the distribution consistency of the random dynamic stress response of thin-walled members in frequency domain and spatial domain under the two kinds of equivalent loads.
【作者单位】：东南大学土木工程学院;
【基金】：国家自然科学基金资助项目(11402052,11572086) 教育部新世纪优秀人才支持计划资助项目(NCET-11-0086) 江苏省自然科学基金资助项目(BK20140616)
【分类号】：TB332

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