Design and analysis of a smart composite pipe joint system integrated with piezoelectric layers under bending

Incorporating with the high electro-mechanical coupling performance of piezoelectric materials, design and analysis of an adhesively bonded smart composite pipe joint system were conducted. In this joint system, piezoelectric layers were integrated into the joint coupler in order to reduce stress concentration in the joint adhesive layer. To theoretically verify the composite action and efficiency of the integrated piezoelectric layers, an electro-mechanical model based on the first-order shear deformation theory was established. This model was able to clarify the energetic characteristics of the proposed joint system on the improvement in the joint strength, which was under the action of a bending moment at the joint ends. The state-space method was utilized to obtain the final analytical solutions, including the peel and shear stress distributions in the adhesive layer. Finally, some numerical examples were calculated to evaluate the effect of the detailed stacking sequence and size of the integrated piezoelectric layers on reducing the stress concentration in the adhesive layer as well as the applied electric fields. These numerical results validated the integrity of the developed adhesively bonded smart composite pipe joint system.