Failure Pattern of Perpendicular Non-Persistent Joints Beneath the Point Load of BM’s Cutter Using Experimental Test and Finite Element Method

In this paper, the failure pattern of non-persistent joint under U shape cutter was studied by experimental test and numerical simulation. For this purpose, 4 gypsum sample with dimension of 5cm*10cm*10cm containing perpendicular non-persistent joint were prepared.  Samples have 2 vertical non-persistent joint with lengths of 1cm and 2 cm. the angle of small joint related to horizontal axis was 0°, 45°, 90° and 135°. This sample was subjected to U shape cutter loading. Concurrent with experimental test, numerical simulation was performed using Franc2d on the non-persistent joint. Totally 12 numerical model was built that some of them have similar configuration with experimental specimens. The results show that perpendicular non-persistent joint configuration has important effect on the failure pattern.  The compressive strengths have minimum value when small joint angle were 45° and 135°. The comparison between experimental results and numerical output shows that the good accordance was established between experimental tests and numerical simulation.