Abstract: A new method is presented for reconstruction of internal transient nonuniform temperature field in solid structures . The proposed method consists of a joint of heat conduction calculation and an inverse analysis for boundary parameter estimation using ultrasonic time of flight by conjugate gradient method or sensitivity method. The principle for internal temperature sensing is based on temperature dependence of the velocity of ultrasonic wave that propagates through solid material. Serial simulation and stability analysis are made， in which classic function form of heat flux or constant temperature is estimated to illustrate the calculating accuracy and the factors of influencing two parameter estimation methods. Comparison experiments with a steel plate which single side is heated by hot water are referred. The temperature gradient and its variation estimated by the two methods agree well with the data measured using thermocouples installed in a steel structure. The results show that the proposed method is a promising means for high accurate reconstruction of internal transient temperature field in solid structure.

Key words: ordnance science and technology, transient temperature field, ultrasound speed measurement of temperature, reconstruction of temperature field, sensitivity method, conjugate gradient method