مرکز منطقه ای اطلاع رساني علوم و فناوري - Thermal Stress Analysis of Functionally Graded Modulus Adhesive Joints

Abstract :

This study examines the thermal residual stress analysis of one-dimensional functionally graded clamped hollow circular plates (FGCP) that are functionally graded on the adhesive layer under in-plane heat flux for different compositional gradient exponents. The material properties of the hollow circular plates were assumed in-plane according to a power-law distribution. The volume fraction of the constituent varies in the plane, not in the plate thickness direction. The transient heat condition and Navier’s equations in polar coordinates describing the one-dimensional thermo-elastic model were discretized using finite-difference method, and the set of linear equations were solved using the pseudo singular-value method. The elasticity modulus in adhesive layers varied from 2000 MPa to 6500 MPa and from 6500 MPa to 2000 MPa, and the grading of this layer was performed for three different compositional grading exponents. The adhesive region and both circular plates are grading along the plane in the radial direction and the compositional gradient exponent of both circular plates is taken as m = 1.0 and this value is held constant for the determination of the results of the grading in the adhesive layer. This study has shown that equivalent stress distributions are significantly influenced by adhesively bonded plates. It has been emphasized that depending on the thermal boundary condition, when the adhesive layer is graded from a low modulus of elasticity to a high modulus of elasticity (2000 → 6500 MPa), the equivalent stress level of the adhesive layer is reduced by 25% compared to the other case. It has been stated that the field of influence of the equivalent stress in the maximum levels shrinks by increasing the increase of the compositional gradient exponent n = 0.1 to n = 1.0. According to the results of the study, the compositional grading upper limit of the adhesive layer with optimum properties and performance in functional graded circular plate joints was set to n = 1.0. It also emphasizes the necessity of grading the adhesive layer so that the thermal stress in the adhesive layer and the interface of the connection can be reduced to a minimum.