Fatigue reliability analysis for vibroseis baseplates

Abstract

AbstractHigh precision vibroseis are widely used in oil and gas exploration. The key component of a vibroseis is its baseplate, suffered from complicated external load. Cracks could be generated in the baseplate, and fractures could occur in the welding parts of baseplates because of an extreme loading. This failure not only reduces the baseplate life significantly, but also affects the quality and precision of the signal excitation seriously. The objective of this work is to study the fatigue behavior of the baseplate by the finite element analysis (FEA) and fatigue reliability analysis. At first, the solid model of the baseplate is built, and the dynamic characteristics are analyzed by FEA based on the orthogonal design scheme. Then the stress distribution and peak area of baseplate are obtained under a series of loadings, thereby producing the stress‐time data of the risky areas. With the S–N curve and the Palmgren–Miner cumulative damage theory, we could therefore predict the baseplate life, and then its fatigue reliability is calculated with the Kriging response surface method. The sensitivity of fatigue reliability with respect to the design parameters is also obtained, and this provides useful information about the importance of design parameters to the fatigue reliability, therefore resulting in the new design that would lead to longer baseplate life, higher quality of the seismic signal excitation, smaller signal distortion and higher accuracy of oil and gas exploration ultimately.