2013/1/8 17:47:07
The short-range interaction effects can be studied using metallographic methods overload This effect can be extended to several thousand or more weeks. Jaw crusher marks extended stagnation depends on the size of the overload. Overload caused by stagnation small overload can be caused by the stagnation of small, medium-sized, up to as much as thousands of weeks. It was discovered that several overload will cause additional stagnation. A high overload may be so that in the subsequent low amplitude cyclic crack extension of ball mills completely stopped. Jaw crusher crack the end zone after unloading the residual stress distribution.
Rift at the top of this residual compressive stress in the subsequent loading process will offset part of the applied tensile stress, therefore jaw crusher effective stress intensity factor of less than plus the actual AK, the the jaw crusher rift extension rate and thus slow down. The closure effects will disappear after a certain number of cycles, with the continuous expansion of the Jaw jaw crusher rift across the plastic zone caused by overload peaks restore jaw crusher rift extension to the normal state. In order to consider the delay of the crack propagation rate of fatigue jaw crusher overload, Wheeler Paris formula introduced a correction factor F.
So, is applied to the over-uploaded peak fatigue jaw crusher machine rift expansion rate of the calculated on for da / dN two FC (AK), correction coefficient F delay parameter its value and then the plastic zone size and by the over-upload ratio between the peak due to the large size of the plastic zone jaw crusher crack length. Load frequency: Overall loaded AK value lower frequency impact Hubei jaw crusher rift extension is very small. High AK values, especially at high temperatures, due to the interaction between frequency and creep loading frequency of da / dN have a significant impact. jaw crusher crack propagation rate has increased with decreasing frequency.