An Experimental Study on Strength of Observation Windows for Research Submarine

Abstract

The collapsing tests have been conducted to investigate the strength of the observation windows for research submarine. The observation windows used in the tests are 90 degrees conical windows, and made of methacrylate plastics. The results of the tests are as follows:- (1) The windows of 30 mm thickness failed generally in flexure, at the pressure of 340∼360 kg/cm^2, while those of 50 mm thickness did not fail at the pressure of 900 kg/cm^2, but yielded plastic deformations. (2) The critical pressure of the windows is given by the following experimental equation: Pcr=5.29(t/D)^2σfcr where, Pcr: critical pressure (kg/cm^2) D: small face diameter of conical windows (mm) t: thickness of windows (mm) σfcr: bending strength of materials (kg/cm^2)