Lifetime Prediction with Combined Hygro‐Thermo‐Mechanical Influences on Thick Layer Adhesives

Semi-structural bonded joints of steel components are exposed to long-term stresses in addition water diffusion, temperature changes and varying external forces during operation. These hygro-thermomechanical loadings lead successive degradation stiffness strength due damage resulting from chemical aging fatigue processes, causing failure the joint when its service life is reached. In following contribution, a methodology presented predict hygro-thermo-mechanically loaded semistructural adhesive with transient FE simulation. The lifetime prediction based on constitutive model viscoelastic part. first part for viscoelasticity consists generalized Maxwell model, which effects humidity properties bond captured by time-temperature time-water concentration shifts. second material an ordinary differential equation evolution. It creep moisture void developments caused local mechanical stress aging. Both parts multiplied Arrhenius-type function account effect change defect growth. interaction studied applying analytical numerical solution equation. All parameters determined using fracture times tests under different climatic conditions loading levels. calculated Fick's boundary condition. diffusion gravimetric measurements. A example setup demonstrate show influence predicted lifetimes hygro-thermo-mechanical cases.