The authors investigated the structural strength of electric-welded straight-line-seam gas pipes with the outside under internal explosive loading. A pipe is considered to be astructure which consists of the basic metal of the pipe, welded seams, lines of alloying of the basic metal and the welded seams. Three schemes leading to failure of pipes, formation of the main crack through the thickness, were tested. Peculiarities of the pipe response were revealed during the tests for each loading scheme. A list of the measuring techniques was formulated for providing informativity of the tests. In the tests according to the scheme of multiple loading of the pipe sample with gradual growth of HE charge power, the authors determined the value of circular plastic strain when the basic metal of the pipes failed. The failure had a viscous character and was followed by high plastic strains. In the tests according to the scheme of single loading by a destroying HE charge, «anomalous» failure of the pipe sample occurred at a circular strain average in the cross-section which was much lower than the critical value for the basic metal. A brittle crack passed along the alloying line, i.e. reduction of plasticity and crack-resistance of the alloying line zone took place. The obtained experimental data were used for the verification of numerical codes simulating dynamic reaction and failure of pipes under high plastic strains. The performed experimental researches demonstrated possibilities of the method of explosive testing in determining failure resistance of gas pipes when reaching high plastic strains.
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