接骨板四点弯曲测定中屈服载荷的获取方法

Method to Calculate the Yield Load of Bone Plate in Four-point Bending Test

该文研究了一种通过接骨板四点弯曲测试获取屈服载荷P的计算方法。该方法采用对测试所得的位移-力(d-F)曲线函数fM(d),再分段平滑计算各段斜率并设定斜率最小限T法寻找fM(d)弹性变形区,然后线性拟合得到斜率S来构建平行移位线函数fL(d),再由线性插值法求取fL(d)与fL(d)逼近交点值从而得到P。该文方法忠实于YY/T 0342—2002的规定,计算过程与测试起始点载荷状况无关,无需原点修正,并易于编程计算。并且在由判定系数R2保障理想拟合水平下设定T值,所得S真实,P值准确。

This paper developed a calculation method to acquire the yield load P of bone plate during four-point bending test. This method is based on the displacement—force （δ-F） curve function fM（δ） obtained from the test, each slope of the curve was calculated using piecewise smooth function and the line segment infM（δ） elastic deformation area was searched by setting the minimum slope T. Slope S was obtained through linear fit so as to build paralel displacement functionfL（δ）. Then, approximating intersection point offM（δ） andfL（δ） was obtained through linear interpolation. Thus, yield load P was acquired. The method in the paper was loyal to YY/T 0342—2002 regulation and was liable to program calculation. The calculating process was nothing to do with whether the initial point during the test was preloaded or unloaded, and there was no need to correct the original point. In addition,T was set in an ideal fitting level guaranteed by the fitting coefficient of determinationR2, and thusS was very close to the real value, andPwas with a high accuracy.