Investigation on the Designing of the Metal Diaphragm in Pulse Solid Rockets

Abstract

To achieve the designing formula of a hard pulse separation device made by a metal diaphragm in a double-pulse solid rocket motor, the fracture mechanics theory and large deflection theory of a circular plate were used to establish the calculating formula of the stress intensity factor of the prefabricated gap on one side of the pulse separation device. The three-dimensional virtual crack-closure technique was used to compute the stress intensity factor of the prefabricated gap. The numerical results agreed with the results calculated by the formula very well. The intensity theory of a circular plate with a multihole was used to establish the checking method of the support strength. The results of the checking method were higher than the numerical results. The checking method was propitious in improving the designing, carrying capacity of the pulse separation device. To verify the accuracy of the formula, the validation tests were carried out. The average opening pressure of the tests of the pulse separation device was 5% higher than the numerical and formula results. Heat flow simulation tests were used to check the carrying capacity of the pulse separation device, and the structure of support remained intact. The results showed that the designing methods in this paper can be applied to design a double-pulse solid rocket motor directly.