弹簧振动失效断口分析

The Fracture Analysis of Spring Vibration Failure

针对某一具体案例对弹簧进行了振动失效断口分析。试验结果表明,弹簧在振动和阀板往复摆动的交变应力作用下,在弹簧双联腿部位产生了疲劳失效;弹簧折弯处由于半径过小,在折弯内表面处产生了初始裂纹,该区是弹簧结构的薄弱区域,疲劳失效往往易起源于该区域;疲劳最终断裂区显示,最后断裂为所受扭转力矩造成;可通过增大双联腿折弯半径,克服折弯缺陷,并在弹簧服役过程中控制轴向串动,防止双联腿部位出现扭转力矩,从而避免该处产生失效。

Vibration failure fracture analysis was carried out for a specific case of the spring,and the test results showed that the spring double-leg-bit produced fatigue failure under alternating stress of vibration and the back and forth swing of valve plate;the bending inner surface generated the initial crack because spring bend radius was too small,and this area was a weak area of the spring structure,and fatigue failure was frequently easily originated in this region;discontinue district fracture showed that the final fracture was caused by the reverse torque.Measures such as increasing the double-leg bend radius,overcoming the bending defects and controlling the axial string action in the spring during service can be employed to prevent the legs of double-bit torques,and thus avoiding the premises to produce failure.