焊接应力及温度场计算机模拟实验

1、材料成形计算机模拟实验一、对一个焊后未打磨的焊接结构件受外载时的应力集中现象进行分析，几何模型如下图所示。焊件材料参数及物理性能如下。条件：对右侧施加一个X方向的拉力，位移为1.5*10-4m 几何参数：长0.08m宽0.05m高0.012m 焊缝余高：0.001m宽度0.01m 材料性能：弹性模量E2.1e11泊松比0.30实验程序为：fini/cle/prep7/unit,siET,1,SOLID45ET,2,SOLID45MPTEMP, MPTEMP,1,0 MPDATA,EX,1,2.1e11 MPDATA,PRXY,1,0.30 /以下是输入模型的几个关键点csys,0k,1,0,0

2、,0 k,2,0,0.012,0 k,3,0.020,0.012,0 k,4,0.025,0,0 k,5,0.030,0.012,0 k,6,0.05,0.012,0 k,7,0.05,0,0 k,8,0.025,0.013,0 k,9,0.0216,0.005,0 k,10,0.0284,0.005,0 k,11,0,0,0.08 /以下是由上述关键点连成线l,1,2 ! line1l,2,3 ! line2l,1,4 ! line3/larc是由三个点连成弧线larc,3,5,8 ! line4larc,3,4,9 ! line5larc,4,5,10 ! line6l,5,6 ! lin

3、e7l,4,7 ! line8l,6,7 ! line9l,1,11 ! line10/以下是由线组成面al,1,2,3,5al,4,5,6al,6,7,8,9vdra,all,10MSHAPE,0,3D MSHKEY,1/以下是对线进行分段LESIZE,1, , ,6, , , , ,1 LESIZE,9, , ,6, , , , ,1 LESIZE,3, , ,12, , , , ,1 LESIZE,8, , ,12, , , , ,1 LESIZE,2, , ,8, , , , ,1 !LESIZE,2, , ,8, , , , ,1 LESIZE,13, , ,24, , , , ,1

4、 LESIZE,4, , ,12, , , , ,1 LESIZE,5, , ,12, , , , ,1 LESIZE,6, , ,12, , , , ,1 vmesh,all!wpoffs，0.025,0,0!vsysm，Y，all!vsysm，Z，all/以下是在相应位置加约束DA,4,UX,0 DA,1,UZ,0 DA,2,UZ,0 DA,3,UZ,0 DA,7,UY,0 DA,14,UY,0 /以下是加应力DA,13,UX,1.5e-4/solsolvefini运行结果：由运行结果得到：=E·=2.1×1011×1.5×10-40.05=6.3&

5、#215;108N/m由上图可以知道应力最大的区域在熔合区，其最大应力值为0.799×108N/m；应力集中系数为：1.27二、焊接过程温度场模拟问题分析：对1个焊接件的两条焊缝的凝固过程的温度场进行分析，几何模型如下图所示。焊条及两块钢板的材料为钢，其物理性能见下表。焊接过程可以归结为一个移动的热源作用下的传热过程，其分析流程主要包括以下步骤：建立模型、设置热分析类型和选项、施加移动热源并求解、查看结果。本例通过双椭球移动热源的加载以模拟该焊接过程，计算结构在焊接过程中的温度变化，以分析结构的性能是否达到设计的要求。双椭球移动热源模型：热输出效率0.60 电压30V电流260A焊接

6、速度0.00117m/s式（1）和式（2）中，a、b 、cf、cb为热源形状参数，q0为热输入功率，ff 、fb 为模型前后椭球的能量分配系数。实验程序为：/CLEAR,NOSTARTFINISH/CONFIG, NRES, 2000 !瞬态分析最大步数/FILNAME,PLASMA A-TIG /PREP7!*! HEAT TREATMENT !*! THERMAL ANSLYSIS !*ET,1,PLANE55ET,2,SOLID70!材料密度MPTEMP,1,20,500,1000,1500,2000MPDATA,DENS,1,1,7930,7930,7930,7930,7930!热膨胀

7、系数MPTEMP,1,20,500,1000,1500,2000MPDATA,ALPX,1,1,1.98E-5,1.98E-5,1.98E-5,1.98E-5,1.98E-5!泊松比MPTEMP,1,20,500,1000,1500,2000MPDATA,NUXY,1,1,0.29,0.29,0.29,0.29,0.29!热传导系数MPTEMP,1,20,500,1000,1500,2000MPDATA,KXX,1,1,21.4,21.4,21.4,21.4,21.4!比热容MPTEMP,1,20,500,1000,1500,2000MPDATA,C,1,500,500,500,500,500

8、!*输入几何模型并剖分网格*RECTNG,0,0.005,0,0.01, RECTNG,0.005,0.01,0,0.01, RECTNG,0.01,0.025,0,0.01,/PNUM,LINE,1/PNUM,VOLU,1/PNUM,AREA,1K,K,0.1NUMMRG, ALL, !合并NUMCMP,LINE !压缩NUMCMP,KP L,1,9LESIZE,2,2, LESIZE,6,2,LESIZE,5,3,2LESIZE,7,3,1/2AMESH,2 !* LREF,2,1,1,OFF,ON!* LESIZE,4,6, LESIZE,2,6,LESIZE,3,10,LESIZE,1

9、,10,AMESH,1 LESIZE,10,8,LESIZE,8,8,LESIZE,6,2,LESIZE,9,2,AMESH,3LESIZE,11,40,VDRAG,1,2,3,11/TITLE,MESH EPLOT ALLSEL*GET,EMAX,ELEM,NUM,MAX !获取结构上最大单元数EMAX VSEL,S,1 ! 选择焊缝, 排序，求出各单元的形心坐标VSEL,S,1 ! 选择焊缝, 排序，求出各单元的形心坐标ESLV,S,1NSLE,S,1EPLOT*GET,NSE,ELEM,COUNT !获取焊缝上最大单元数NSE *DIM,NE,NSE ! 定义NE数组，记录所有单元编号

10、*DIM,NEX,NSE ! 定义NEX数组，记录所有焊缝单元的系统坐标系的X坐标*DIM,NEY,NSE ! 定义NEY数组，记录所有焊缝单元的系统坐标系的Y坐标*DIM,NEZ,NSE ! 定义NEZ数组，记录所有焊缝单元的系统坐标系的Z坐标*DIM,NEORDER,NSE ! 定义单元编号数组，按几何位置排列，按层，道，角度的顺序MINE=0 ! 定义初值，记录在循环中每次选中的单元II=0*DO,I,1,EMAX*IF,ESEL(I),EQ,1,THENII=II+1 NE(II)=I ! 焊缝上单元顺序排列 *ENDIF*ENDDO!获取焊缝单元的坐标，分别存储于数组NEX,NEY,

11、NEZ中 *DO,I,1,NSE *GET,NEX(I),ELEM,NE(I),CENT,X *GET,NEY(I),ELEM,NE(I),CENT,Y *GET,NEZ(I),ELEM,NE(I),CENT,Z *ENDDO *CFOPEN,XYZ,TXT,APPEND*VWRITE(' NE, X, Y, Z') *DO,NP,1,NSE *VWRITE,NP,(NEX(NP),(NEY(NP),(NEZ(NP)%6I%12.2F%12.2F%12.2F!(F6.0,',',F10.6,',',F10.6,',',F10.3,

12、',') *ENDDOALLSEL,ALL!*进入瞬态温度场分析求解*/SOLU ! 进入求解器 TUNIF,20 ! 定义初始温度ANTYPE,TRANS ! 设置为瞬态求解!KBC,1KBC,0OUTRES,ALL ! 定义结果输出TOFFST,273 ! 定义温度偏移量ALLSEL,ALL ! 选择所有节点AUTOTS,ON ! 打开自动时间开关!PARAMETER OF THE PLASMA ARCEITA=0.60 VOLTAGE=30CURRENT=260SPEED=0.00117ra=8/1000rb=4/1000rc1=1.5/1000rc2=4.5/1000f

13、raction1=0.5fraction2=1.5thick=10/1000 DT=0.1/40/SPEEDZ0=0TM=1E-3DTIME=DT*DIM,GENQ,NSE ! 定义GENQ数组，记录焊缝单元的热生成率*DO,ITM,1,40, !设置计算步数 TM=(ITM-1)*DT+1e-3 TIME,TM !当前时间为TM !给本次加载步中受热部分的单元加载 !本次加载步中受热部分的单元加载 ZMAX=Z0+SPEED*TM+10*RC1 ZMIN=Z0+SPEED*TM-10*RC2 *DO,II,1,NSE *IF,NEZ(II),LE,ZMAX,THEN *IF,NEZ(II),

14、GT,0,THEN Q1=6*1.732*FRACTION1*EITA*VOLTAGE*CURRENT/(3.1416*1.5)*RA*RB*RC1) INSIDE1=-3*(NEZ(II)-SPEED*TM)*2/RC1/RC1) INSIDE2=-3*(NEX(II)*NEY(II)/RB/RB) INSIDE3=-3*(THICK-NEY(II)*2/RA/RA) INSIDE=INSIDE1+INSIDE2+INSIDE3 *IF,INSIDE,LE,-10, THEN Q2=0 *ENDIF *IF,INSIDE,GT,-10, THEN Q2=EXP(INSIDE) *ENDIF

15、GENQ(II)=Q1*Q2 BFE,NE(II),HGEN,GENQ(II) *ENDIF *ENDIF *IF,NEZ(II),LT,0,THEN *IF,NEZ(II),GT,ZMIN,THEN Q1=6*1.732*FRACTION2*EITA*VOLTAGE*CURRENT/(3.1416*1.5)*RA*RB*RC2) INSIDE1=-3*(NEZ(II)-SPEED*TM)*2/RC2/RC2) INSIDE2=-3*(NEX(II)*NEY(II)/RB/RB) INSIDE3=-3*(THICK-NEY(II)*2/RA/RA) INSIDE=INSIDE1+INSIDE2

16、+INSIDE3 *IF,INSIDE,LE,-10, THEN Q2=0 *ENDIF *IF,INSIDE,GT,-10, THEN Q2=EXP(INSIDE) *ENDIF GENQ(II)=Q1*Q2 BFE,NE(II),HGEN,GENQ(II) *ENDIF *ENDIF *ENDDO ALLSEL SOLVE !求解 !删除本次加载步中受热部分的单元荷载，为下一步加载做准备 *DO,II,1,NSE *IF,NEZ(II),LT,ZMAX,THEN *IF,NEZ(II),GT,ZMIN,THEN BFEDE,NE(II),HGEN,GENQ *ENDIF *ENDIF *ENDDO *ENDDO /POST1/VIEW, 1, -0.8 , 0.34 , 0.468/ANG, 1, -6.5 /REPLO /AUTO,1 /REP,FAST*DO,II,1,40SET, , ,IIPLNSOL,TEMP,0,10*ENDDO/VIEW, 1, -0.8 , 0.34 , 0.468/ANG,1 /REP,FAST