Notched fatigue strength prediction of SiCp/Al composites based on the three-dimensional space vector stress field intensity method
In order to consider the influence of stress gradient on the fatigue strength of SiCp/Al composite structure,a notched fatigue strength prediction method of SiCp/Al composite was developed based on the three-dimensional space vector stress field intensity method(TSVFM)and the fatigue strength of smooth specimen.In the TSVFM,the equivalent stress integral forms of classic one-dimensional stress field intensity method and effective distance point stress field intensity method were applied respectively,which avoided the construction of three-dimensional weight function and artificial determination of fatigue damage region.The fatigue test scheme of SiCp/2009Al composite smooth specimen was determined by up-and-down method,and the axial(R=-1)fatigue strength corresponding to 107 cycles of SiCp/2009Al composite was 180.91 MPa.The fatigue life distribution of SiCp/2009Al was obtained by the scattered point method.The fatigue test results of smooth specimen showed that there was an obvious platform area in the stress-life relationship of SiCp/2009Al composite.The axial(R=-l)fatigue test of notched specimen of SiCp/2009Al composite was carried out by step-by-step loading method,and the fatigue strength of notched specimen was 82.2 MPa.The fatigue strength prediction results of notched specimen were in good agreement with the test results,and the maximum error was within 10％.The notched fatigue strength prediction method of SiCp/Al composites based on the ETSVFM was better than the CTSVFM.
SiCp/Al compositesfatigue strengthnotched fatiguethree-dimensional stress field intensityhigh cycle farigue test
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