Development of heat input estimation technique for simulation of shell forming by line-heating

A new hypothesis regarding beat transmission during line heating is proposed. It states that the distribution of the temperature of the gas adjacent to the plate, T-G, and the overall local heat transfer coefficient, alpha, depend only on the distance from the torch. An identification technique for TG and alpha is developed. The validity of the employed hypothesis and the proposed technique is demonstrated by comparing the measured and identified T-G during a spot heating test. The plate temperature calculated by direct heat conduction analysis closely approximates the one measured for the spot and line heating tests, when T-G and a identified from the spot heating test are used as the thermal boundary conditions. This indicates that heat transmission can be estimated for any desired plate shape, dimension and torch movement history, based solely on the spot heating test results.