A High-Temperature Piezoelectric Accelerometer Operating in Symmetric Shear–Bending Coupling Mode

(BS-PT) ceramic rings, operating in symmetric shear-bending coupling vibration mode is proposed. This coupling mode enhances effective electromechanical coupling through a charge amplification factor, yielding a high sensitivity (22.8 pC/g), approximately three times that of conventional shear-type accelerometers at room temperature. The device exhibits stable performance, maintaining a sensitivity of 14 pC/g after repeated thermal cycling between room temperature and 260 °C and during forced vibration tests, while exhibiting a linear response across a wide frequency range. Operation at even higher temperatures is feasible by employing piezoelectric materials with higher Curie temperatures. The demonstrated combination of high sensitivity, thermal reliability, and structural robustness underscores the potential of this accelerometer for applications in aerospace, energy, and nuclear engineering.