XFEM-Based Study of Fatigue Crack Propagation in Rocket Deflector Troughs under Coupled High-Temperature and Impact Conditions

Abstract

This research investigated fatigue crack propagation on the lower surface of rocket deflector troughs in offshore rocket launch platforms. Initially, a numerical model of an offshore rocket launch platform was established using ABAQUS based on the Extended Finite Element Method (XFEM). Subsequently, two variable parameters—the initial crack length and initial tilt angle—were introduced. This research systematically analysed the impact of these parameters on the fatigue crack propagation patterns in both the maximum stress and maximum deformation regions of the deflector channels under the combined conditions of high temperature and impact. Finally, the research indicated that the propagation length of surface cracks in the deflector trough exhibited an initial increase followed by a decrease with the rise in the pre-set inclination angle. Notably, the stable propagation rate of the crack in the region of maximum deformation surpassed that observed in the region of maximum stress. Through meticulous comparative analysis, it was evident that temperature loading significantly exacerbated the initiation and propagation of cracks, particularly in the upper region of the deflector channel’s lower surface.

Rolling Mechanism of Launch Vehicle during the Prelaunch Phase in Sea Launch

“…Pua et al [27] simulated the impact of hydrogen combustion following a hydrogen leak accident on offshore launch platforms and the preventive effect of protective walls, demonstrating that wall design can effectively protect rockets from combustion impacts. Xiong et al [28] studied the influence of initial crack length and initial tilt angle on fatigue crack propagation on the lower surface of rocket deflector channels of offshore rocket launch platforms using the Extended Finite Element Method (XFEM). Yu et al [29] indicated that launch vehicle lateral eccentricity during launch can induce significant rolling motion in the platform.…”