Torsional fatigue behavior of adhesively joined tubes

A commonly utilized method of joining metal tubes to each other is to bond them by the use of adhesives. Structures created in such a manner are frequently subjected to various types of loading, i.e. tension, compression, bending, torsion or combination of these. Of particular interest and significance in many industries is what happens when torsional cyclic loading is applied to such joints, which subject the joint to fatigue. The joint configuration will perform differently depending upon various variables, i.e. bond gap, bond length, etc. …. The extended usage of the metal structures mentioned above is frequently encountered in the field and inspections in industrial use are intended to provide information on the soundness of these structures in general and joints in particular and to identify the amount of accumulated damage that is deemed acceptable at the time of inspection. The successful evaluation of these structures without doing destructive testing is of immense value to industrial users. NDT procedures (non-destructive techniques) to evaluate the damage to the structures present a better approach because they lead to better comprehension of the residual stresses present within the joints, lead to an improved and more effective utilization of materials and allow for prediction of the period of the utility of the joint. A comprehensive effort is under way to study the fatigue caused phenomena of adhesively joined aluminum tubular connections subjected to torsional cyclic loading. This includes the testing of a popular and widely utilized adhesive; which entails the design of the test rig, instrumentation, and post data analysis. Assessments of damages to the joints will be carried out upon conclusion of the experimental work as well as the analytical study enabling prediction of the phenomena encountered to assist the designer when planning such joints.