摘要
利用实验室振动加载技术来等效模拟实际工况的随机振动载荷,以研究结构的振动环境适应性,是工程界通用的做法。文中讨论了随机振动载荷动力学等效的过程与方法,针对小阻尼稀疏模态结构,给出了基于结构振动响应等效的随机振动载荷等效关系的工程应用表达式和评价等效载荷对疲劳损伤影响的方法。简支梁数值模拟表明,通过文中方法设计的等效随机振动载荷,不仅可以获得变化不大的结构响应,而且疲劳损伤等效结果也可以满足工程应用精度要求。
In order to study the adaptability of a structure to certain vibration environment, it is a general method in engineering to equivalently simulate the field vibration excitation using lab loading technique. The procedure and method about the dynamic equivalence of random vibration excitation are discussed in this paper, and an approximate formula for designing equivalent vibration excitation is presented based on equivalent structural response, displacement, stress, for the structure charactered by light damping and sparse mode. Also, a method is presented to estimate the effects of equivalent vibration excitation to the fatigue damage accumulation. An example of numerical simulation for simply supported beam is applied to verify rationality of the proposed method. It shows that the structure response （displacement and stress） nearly present similar excitation by the equivalent excitation based on proposed method, while the fatigue damage accumulation of a simply supported beam remains enough precision for engineering application.
出处
《实验力学》
CSCD
北大核心
2007年第6期568-574,共7页
Journal of Experimental Mechanics
关键词
随机振动
振动载荷
动力学等效
振动响应
小阻尼结构
稀疏模态
random vibration
vibration excitation
dynamic equivalence
vibration response
light damping system
sparse modal
