Pure Bending Moment 하(下)에 있는 Notched Strip에서의 Notch Angle의 비대칭적(非對稱的) 변화(變化)에 의(依)한 응력집중계수(應力集中係數)의 변화(變化)

A Photoelastic Study on Change of Stress Concentration Factor Due to Unsymmetrical Change of Notch Angle

It is investigated that in what shape the stress concentration factor of a notched strip under pure bending changes due to unsymmetrically varying notch angle. Four models made of CR-39, having parameters of r/d-0.225, h/r=4; r/d=0.225, h/r=2; r/d=0.4, h/r=4 and r/d=0.4, h/r=2 respectively as shown in Fig.1, Fig.2 and Table are tested with the use of polariscope. For each model, notch angle is unsymmetrically varied from $0^{\circ}$ to $180^{\circ}$ at intervals of $15^{\circ}$ as shown in Fig. 1 and Fig. 2. The results of this experiment are Fig. 7 and Fig. 8 and the following are deduced. As notch angle increases 1) from $0^{\circ}$ to $50^{\circ}$, the decrement of concentration factor is slight. 2) from $50^{\circ}$ to 90, the decrement of concentration factor is a little steeper. 3) from $30^{\circ}$ to $140^{\circ}$, the decrement of concentration factor is slight. 4) from $140^{\circ}$ to $180^{\circ}$, the decrement is very steep with an abrupt with an abrupt change in the neighborhood of $140^{\circ}$.