细长体分布式载荷的缩聚及其在气动伺服弹性地面模拟中的应用

Condensation of Distributed Loads on Slender Body and Its Application in Aeroservoelastic Ground Simulation

气动伺服弹性地面模拟试验是近年发展出的一种新型气动弹性地面试验技术,其中的一个关键问题就是非定常气动力的缩聚,即将飞行器所受的分布式气动载荷缩聚为少数几个集中载荷。传统缩聚方法以简单的力、力矩平衡准则对分布力进行处理,或者是通过求解静不定问题,把支反力作为缩聚力,均存在一些缺点。本文提出一种基于一维样条插值的细长体分布式载荷缩聚方法,采用关键模态相似准则来优化缩聚点位置,以达到细长体在缩聚点集中式载荷作用下的动响应与分布式载荷作用下的动响应最为接近的效果。利用简支梁、悬臂梁两个算例验证了所提出的分布式载荷缩聚方法的精度,并将该方法应用于一个细长体导弹的气动伺服弹性地面模拟中。数值仿真表明,所提方法能够快速准确将导弹的非定常气动力缩聚成实时的集中力,满足气动伺服弹性地面模拟试验的精度和快速性要求。

Aeroservoelastic ground simulation test is a new aeroelastic ground test technology developed in recent years.One of the key problems is the condensation of unsteady aerodynamic forces,that is,the distributed aerodynamic loads on flight vehicles are condensed into a few concentrated loads.The traditional condensation method deals with the distributed force with a simple force and moment balance criterion,or takes the support reaction forces as the condensation forces by solving the statically indeterminate problem.These methods have some disadvantages.In this paper,an equivalent condensation method based on one-dimensional spline interpolation is proposed for the distributed loads of slender vehicles,and the key mode similarity criterion is used to optimize the location of condensation points,so as to achieve the effects that the dynamic responses of slender body under the concentrated loads of condensation points are the closest to that under the distributed loads.The accuracy of the proposed condensation method is verified by two examples of simple supported beam and cantilever beam,and the condensation method is applied to the aeroservoelastic ground simulation of a slender missile.Numerical simulation shows that the unsteady aerodynamic force of the missile can be condensed into real-time concentrated force quickly and accurately by using this method,which meets the accuracy and rapidity requirements of aeroservoelastic ground simulation test.