UTILIZATION OF THE RELATIVE RIGIDITY CONCEPT TO PREDICT THE FAILURE OF PIPE SYSTEMS UNDER EXPLOSIVE LOADS

The interaction between loading plates and supporting structures is ve ry much dependent upon the relative rigidity of the system. This paper first illustrates how an indiscriminate application of the relative r igidity concept can lead to erroneous conclusions in such systems. The paper then applies the concept to explain reported observed failure m odes in pipe systems under explosive loads. Numerical studies are pres ented which simulate the behaviour of square pipe systems under static and explosive loads using the concept of relative rigidity in conjunc tion with the finite element method. The results of the analysis confi rm the hypothesis of the relative rigidity concept. Experimental verif ication of the theoretical predictions and numerical modelling results are obtained by simulating the explosive failure patterns in simple f reezing experiments. The analysis presented in this paper demonstrates the importance of the concept of relative rigidity for explaining cer tain kinds of observed failure and fracture phenomena.