Study on Modeling and Optimization Method for High-Temperature Resistance and Miniaturization of Electromagnetic Ultrasonic Transducers Under Variable Loads
Abstract：Electromagnetic acoustic transducers (EMATs) face permanent magnet demagnetization issues in high-temperature applications. This makes online inspection under extreme conditions very difficult. Modern aerospace systems demand compact, high-performance sensors that can work in harsh environments, such as high temperature, high speed, and confined spaces. Current solutions often rely on external cooling, high-temperature materials, or thermal barriers. However, few studies explore structural optimization under combined thermal and mechanical loads. To achieve high-temperature miniaturization, this paper presents a new probe design for EMATs. A thermodynamic finite element model of the probe was constructed. The key idea is to treat the outer shell as both a design variable and the main carrier of thermal load. Optimized Latin hypercube sampling is used to generate an efficient set of initial design points across the parameter space. A sensitivity study is then carried out to evaluate the effects of each geometric parameter. It is found that the shell thickness is identified as the dominant factor governing both thermal and mechanical responses. The results reveal a counterintuitive finding, reducing shell thickness—typically expected to increase stress or temperature—actually lowers both peak temperature and stress in the system. This happens because the thinner shells improve heat dissipation and reduce thermal mass. More importantly, thermal and mechanical responses are not in conflict, and instead, they are simultaneously improved through the same design variable: shell thickness. This breaks from traditional design, where thermal and structural goals often compete. The method enables compact, high-temperature EMATs without additional cooling or exotic materials. It is demonstrated that the integrated thermomechanical optimization can align multiple performance goals into a unified design strategy. The approach holds great promise for other high-temperature sensing or actuation systems in aerospace engines, nuclear reactors, and advanced manufacturing processes, where size, weight, reliability, and thermal resilience are critical.
2026, Vol. 47 
