Mine-used big scale fixed equipments are important electromechanical device in coal mine, guaranteeing the safe operation of these big scale equipment is the key of safe management in coal mine.
矿用大型固定设备是煤矿重要的机电装备，确保大型设备的安全运行是煤矿机电和安全管理的重要一环。
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Two-scale expansion method has been extended to the electromechanical coupling problem, the fe program is coded and the effective properties of piezoelectric materials with defects are predicted.