问题描述：半径为8mm的钢球和一刚性平面接触，在球顶施加集中力f的作用，求hertz接触半径钢球材料参数：弹性模量：e=220gpa，泊松比v=0.3载荷；F=5000n/FILENAME,GANGQIUJIECHUFENXI/TITLE,GANGQIUJIECHUFENXI/PREP7ET,1,PLANE82ET,2,PLANE2ET,3,CONTA178KEYOPT,1,3,1KEYOPT,2,3,1KEYOPT,3,2,4R,1RMOD,1,7,1MP,EX,1,220E3MP,PRXY,1,0.3LOCAL,11,1,0,8,0K,1,8,-90K,2,8K,3,7.5,-90K,4,7.5K,5K,6,8,-82.65K,7,7.5,-82.65L, 1,3L,2,4L,6,7LESIZE,ALL,1A,1,6,7,3A,6,2,4,7A,3,7,4,5LOCAL,12,0,0,8,0ARSYM,Y,1,3,1NUMMRG,ALLESIZE,4LESIZE,4,5LESIZE,5,5LESIZE,10,1LESIZE,12,1LESIZE,6,8,8LESIZE,7,8,0.0125LESIZE,9,6,0.2TYPE,1AMESH,1,2,1AMESH,4,5,1TYPE,2AMESH,3,6,3CSYS,0N,1001,-1,1E-8TYPE,3REAL,1EN,205,1001,2EN,201,1001,4EN,202,1001,6EN,203,1001,8EN,204,1001,10EN,206,1001,31EPLOTFINISH/SOLUD,1001,ALLNSEL,S,LOC,X,0D,ALL,UX,0NSEL,S,LOC,Y,0D,ALL,UY,0ALLSELFK,8,FY,-5000SOLVEFINISH/POST1PLNSOL,U,XPLNSOL,U,YESEL,TYPE,3NSELETABLE,RFOR,SMISC,1SSUM*GET,EMAX,ELEM,ENUM,ETAB,RFOR*IF,GRFR,EQ,0.0,EXIT*ENDDOESEL,ELEM,(ENUM-1)NSEL*GET,NMIN,NODE,0,NUM,MINNODX=NX(NMIN)NUX=UX(NMIN)CONTACT_RADIUS=NODX+NUX*STATUS,PARMFINISH/EXIT,ALLSET,FIRSTPLDISP,0SET,NEXTPLDISP,0SET,NEXTPLDISP,0SET,NEXTPLDISP,0SET,NEXTPLDISP,0FINISH/EXIT,ALL