Pulse pressure life prediction and analysis of electric water heater liners based on HyperWorks

WANG Xu; ZHANG Haipeng; XIE Jiameng; TONG Tongtong; GAO Xiang

doi:10.19784/j.cnki.issn1672-0172.2025.05.010

Abstract：To address the insufficient accuracy of traditional S-N curve-based methods in predicting the low-cycle pulse fatigue life of thin-walled electric water heater liners,a fatigue life prediction method based on the strain-life(ε-N)theory is proposed.Leveraging the HyperWorks platform,a pulse pressure life prediction model for the liner was constructed by combining OptiStruct static analysis under extreme conditions and the ε-N fatigue calculation module in HyperLife.The predicted fatigue life for the original liner model was 23,829 cycles,while physical testing yielded 18,926 cycles,resulting in an error of 25.9%.By optimizing the head curvature design,the plastic strain at critical areas was significantly reduced.The predicted life for the optimized model increased to 175,864 cycles,representing a 7.38-fold improvement over the original design.Physical testing of the optimized liner confirmed a life of 160,725 cycles,with the error reduced to 9.4%.The study demonstrates that this method effectively quantifies low-cycle fatigue damage in the liner,achieving prediction accuracy suitable for engineering applications.It drastically reduces the traditional reliance on physical testing,shortening the development cycle from weeks to 2 days～3 days and cutting R&D costs by approximately 70%,thus providing an efficient and high-precision solution for the reliability design and life prediction of pressurized components in household appliances.