A Study On The Virtual Fatigue Test For Military Construction Vehicles

The work in this paper is supported by the General Armament Department in the project"Theory & Method Researching on the Riding Reliability Simulating Tests of Military Construction Vehicles (CV)".By integrating the technologies of virtual prototype (VP), finite element analysis (FEA), fatigue theories etc., the key technologies of virtual fatigue test (VFT) such as the VP's modeling, the process control of virtual tests, virtual loading spectra acquiring, virtual fatigue life prediction etc, have been researched. Then, by considering of particularities of the structure of military CVs and their operation environments, the CV in this paper was divided into two systems——the working device system and the chassis system. Each system will be modeled and tested separately based on its own characteristics. Finally, by integrating the software such as MSC.ADAMS, MSC.Patran, MSC.Nastran,and MSC.Fatigue, we found the process of the VFT for the two systems separately. Then the two VFTs made up the whole VFT system for military CVs.The VPs of some loading device and the chassis of a high-speed wheeled scraper were built up under the ADAMS. Base on the VFT system, at first, the loading spectra that both in time domain and modal domain were acquired by the operation simulation and virtual road riding simulation separately. Second, VFTs were done with those time domain force spectra and modal displacement spectra (use the method calls modal stress recovery (MSR) to recover modal node stress spectra). Finally, the two systems'metal structure parts'fatigue lives and their fatigue safe factors were obtained. By matching these VFTs'result data with the real vehicle test's results and standards,the validity of VFT system in the reliability demonstration test of the military CV was proved.This VFT system terminates the history of the real vehicle road riding test or proving ground (PG) test as the main methods of military CV's reliability test. Implementing this system to a construction vehicle for fatigue & durability experiment, taking it as a supplement for the real vehicle test, can effectively reduce the real vehicle experiment's risk and working intensity, save experiment expense. The work in this paper could take significant advantage on improving the CV's reliability test implementation level and accelerating the update of the military CVs.