FINITE ELEMENT STRESS ANALYSIS AND STRENGTH EVALUATION OF ADHESIVE BUTT JOINTS OF CIRCULAR PIPES COMBINING COUPLING COLLAR WITH ADHESIVE SUBJECTED TO INTERNAL PRESSURE, TEMPERATURE CHANGE AND EXTERNAL BENDING MOMENTS

摘要

The interface stress distributions between the coupling collar, the adhesive and the pipes of the joint subjected to an internal pressure, a temperature change and bending moments are analyzed by using the elastic finite element method (FEM). The experiment of the rupture test of the joints manufactured by pipes made of structural steel (S45C, JIS) and epoxide adhesive was carried out by applying the above loads to the joints. From the numerical calculations, the following results were obtained: (1) the stress distributes uniformly at the interface except near the edges, (2) the stress becomes singular at the edges of the interfaces and (3) the stress distribution at a half part of the interface increase as the external bending moments increase and also Young's modulus of the adhesive increases. From the experiments, the following results were obtained: (1) the joint strength (evaluated as a 95% non-rupture probability) under both the internal pressure and the temperature change increases as the coupling length increases and (2) the joint strength under both the internal pressure and the temperature change decreases when the external bending moment is applied to the joint. Furthermore, the numerical results are in fairly good agreement with the experimental results.