Response of Finite Continuous Structures with Discrete Masses to Impact and Its Application to Pyroshock Simulation
In the run-up of aerospace missions, involved space modules are subjected to various tests one of which is the pyroshock test. Pyroshocks are caused by controlled explosions of ordnance devices in order to e.g. span solar sails or detach rocket stages. They transiently excite the sophisticated structures of space modules, which may cause severe damage and high costs if involved parts have not been properly tested on earth. Therefore, tests have been developed in order to simulate pyroshocks. Aerospace administrations make high demands on the fulfillment of well defined guidelines including the generation of the Shock Response Spectrum (SRS) specified for each module. The latter can be computed based on the acceleration signal at a certain point and evaluates the dynamic loading of a structure. One common testing procedure is realized by the replacement of the explosive by the impact of a hammer pendulum hitting a plate on which the test specimen is mounted. The mechanical problem consisting of a contact problem between a rigid sphere and a finite plate with point masses including subsequent in-plane and out-of-plane wave propagation is investigated. The overall goal is to calculate the acceleration at the module with respect to the input parameters such as impact velocity, mounting and impact position and, therefore, make pyroshock tests analytically predictable. The problem is solved analytically in space domain by using HERTZian contact theory as well as the GALERKIN-procedure and simple numerical integration in time domain. The evolution strategy is used in order to facilitate the search for the optimum set of input variables leading to the desired SRS. All calculated results are compared with experimental and FEM data and lead to very good coincidence. Therefore, pyroshock tests based on the mentioned procedure can be simulated and, thus, predicted which also allows for a better analytical understanding of the effects of pyroshocks on structures. In addition, expensive and time consuming testing procedures can be optimized.
Alexander Lacher Nikolas Juengel Maik Renning Utz von Wagner
Technische Universitat Berlin, Department of Applied Mechanics, Chair of Mechatronics and Machine Dy Technische Universitat Berlin, Department of Applied Mechanics,Mechatronics and Machine Dynamics,Ein Technische Universitat Berlin, Department of Applied Mechanics, Mechatronics and Machine Dynamics,Ei
国际会议
The 4th International Conference on Mechanical Engineering and Mechanics(第四届国际机械工程与力学会议)
苏州
英文
575-580
2011-08-11（万方平台首次上网日期，不代表论文的发表时间）