Xiaoli Wei¹, D. A. Makhloof^1,2, Xiaodan Ren^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.134, No.1, pp. 9-34, 2023, DOI:10.32604/cmes.2022.020160 - 24 August 2022

Abstract Fatigue failure phenomena of the concrete structures under long-term low amplitude loading have attracted more attention. Some structures, such as wind power towers, offshore platforms, and high-speed railways, may resist millions of cycles loading during their intended lives. Over the past century, analytical methods for concrete fatigue are emerging. It is concluded that models for the concrete fatigue calculation can fall into four categories: the empirical model relying on fatigue tests, fatigue crack growth model in fracture mechanics, fatigue damage evolution model based on damage mechanics and advanced machine learning model. In this paper, a More >

Borui Yang¹, Jun Luo², Bo Wan^1,*, Yutai Su^1,3, Guicui Fu¹, Xu Long^3,*

CMES-Computer Modeling in Engineering & Sciences, Vol.130, No.2, pp. 1113-1134, 2022, DOI:10.32604/cmes.2022.018037 - 13 December 2021

Abstract A thermal fatigue lifetime prediction model of ceramic ball grid array (CBGA) packages is proposed based on the Darveaux model. A finite element model of the CBGA packages is established, and the Anand model is used to describe the viscoplasticity of the CBGA solder. The average viscoplastic strain energy density increment ΔWave of the CBGA packages is obtained using a finite element simulation, and the influence of different structural parameters on the ΔWave is analyzed. A simplified analytical model of the ΔWave is established using the simulation data. The thermal fatigue lifetime of CBGA packages More >