Modeling and characteristic analysis of the multilayer bimorph and deflector-feedback rod assembly in a deflector jet servo valve

The deflector jet servo valve driven by multilayer bimorph achieves exceptional performance for advanced aerospace applications, with critical advantages of fast response, high precision and compact structure. The valve output characteristics is fundamentally determined by the output characteristics of its multilayer bimorph and deflector-feedback rod assembly, where existing models fail to accurately predict behavior under limited working conditions. This study develops a mathematical model to precisely characterize the output characteristics of assembly, incorporating adjustable clamping length and reduction of effective driving force. With finite element analysis and experiments, static characteristics of the assembly are analyzed. Experimental validation demonstrates the accuracy of model, reducing maximum relative errors by 50.5% in assembly end feedback force prediction and 66% in deflector displacement estimation compared to conventional approaches. This work provides not only essential theoretical support for multilayer bimorph applications in complex structural load, but also provides theoretical support for developing precise control algorithms with mechanical feedback. The improved model enables optimization of servo valve design and assembly precision while maintaining system performance.