《lecture6-cAbaqusStandard中的接触问题.ppt》由会员分享，可在线阅读，更多相关《lecture6-cAbaqusStandard中的接触问题.ppt（19页珍藏版）》请在三一办公上搜索。
1、 Dassault Systmes,2008,Abaqus/Standard中的接触问题,Lecture 6,Introduction to Abaqus/Standard and Abaqus/Explicit,L6.2,简介,将接触作为模型定义的一部分主/从方法中网格密度的考虑Abaqus/Standard中的接触逻辑习题5：密封接触,Dassault Systmes,2008,将接触作为模型定义的一部分,Introduction to Abaqus/Standard and Abaqus/Explicit,L6.4,将接触作为模型定义的一部分,在Abaqus/Standard 整个con
2、tact定义作为模型数据必须在step之前接触对在分析历程中可以使用*MODEL CHANGE选项激活或者不激活*MODEL CHANGE,TYPE=CONTACT PAIR,ADD|REMOVEsurface_1,surface_2,Dassault Systmes,2008,在严格的Master/Slave定义中要考虑网格密度,Introduction to Abaqus/Standard and Abaqus/Explicit,L6.6,在严格的Master/Slave定义中要考虑网格密度,从属表面应该是网格划分得更精细的表面.如果网格密度相近似，从属表面应由更为柔软的材料组成.,Inc
3、orrectMaster surface placed on fine mesh Gross penetration into slave surface.,CorrectMaster surface placed on coarse mesh Minimal penetration into slave surface.,Dassault Systmes,2008,在 Abaqus/Standard中CONTACT规则,Introduction to Abaqus/Standard and Abaqus/Explicit,L6.8,在 Abaqus/Standard中CONTACT规则,对于
4、点接触需要施加约束有多种不同的约束施加方法.缺省情况下,Abaqus/Standard使用拉格朗日多项式方法.对于每个潜在的接触点，接触条件通过单个的、非线性的、不等式约束描述：其中h 为“侵彻”，uN 为自由度,Introduction to Abaqus/Standard and Abaqus/Explicit,L6.9,在 Abaqus/Standard中CONTACT规则,一个增量步内状态的原理图（默认状态）,检查求解是否收敛,4,开始增量步,结束增量步,Yes,(至少一个收敛准则不满足),确定是否趋于收敛,5,(减少增量步大小并重新求解),确定接触状态的变化,3,No,(在收敛容差范
5、围内),No,Yes,Newton 迭代,Introduction to Abaqus/Standard and Abaqus/Explicit,L6.10,在 Abaqus/Standard中CONTACT规则,默认的接触算法（参考前页的流程图）确定每个点当前的接触状态（接触或张开）对于一个分析步的第一个增量步，基于初始模型的状态；否则，基于求解的外插 计算刚度，施加相应的接触约束的影响。形成系统方程并求解。接触压力和间隙是否与接触状态一致。接触状态改变（张开/闭合或粘结/滑移）通常导致系统方程的重大变化。由接触状态改变产生的迭代被标记为严重不连续迭代(SDIs),1,2,3,Introdu
6、ction to Abaqus/Standard and Abaqus/Explicit,L6.11,在 Abaqus/Standard中CONTACT规则,是否达到收敛？默认的，Abaqus量化与SDIs关联的接触不相容性。那些关于接触状态的不相容性必须十分小才能达到收敛。也必须确保力的剩余误差和求解修正很小才能达到平衡如果接触状态和平衡条件满足各自的收敛准则，这个增量步完成如果没有达到收敛，它可能会收敛吗？Abaqus估算趋势，例如连续迭代中接触状态改变的次数，以确定是否继续迭代或减小增量步长重算如果可能收敛，更新基于 的接触条件和刚度，重新求解系统方程；否则，利用更小的增量步重试。,4,
7、5,3,Introduction to Abaqus/Standard and Abaqus/Explicit,L6.12,在 Abaqus/Standard中CONTACT规则,接触打印输出例子参考:Example Problem 1.3.4,“Deep drawing of a cylindrical cup”状态(.sta)文件:SUMMARY OF JOB INFORMATION:MONITOR NODE:200 DOF:2 STEP INC ATT SEVERE EQUIL TOTAL TOTAL STEP INC OF DOF IF DISCON ITERS ITERS TIME/
8、TIME/LPF TIME/LPF MONITOR RIKS ITERS FREQ 1 1 1 1 1 2 1.00 1.00 1.000 0.000 2 1 1 0 1 1 2.00 1.00 1.000 0.000 3 1 1 10 0 10 2.01 0.0100 0.01000-0.000600 3 2 1 7 1 8 2.02 0.0200 0.01000-0.00120 3 3 1U 10 0 10 2.02 0.0200 0.01500-0.00120 3 3 2 5 0 5 2.02 0.0238 0.003750-0.00142 3 4 1 3 1 4 2.03 0.0294
9、 0.005625-0.00176 3 5 1 2 3 5 2.04 0.0378 0.008438-0.00227 3 6 1 4 1 5 2.05 0.0505 0.01266-0.00303 3 7 1 4 1 5 2.07 0.0695 0.01898-0.00417 3 8 1 6 1 7 2.10 0.0979 0.02848-0.00588 3 9 1U 8 0 8 2.10 0.0979 0.04271-0.00588 3 9 2 4 3 7 2.11 0.109 0.01068-0.00652 3 10 1 2 3 5 2.12 0.125 0.01602-0.00748 3
10、 11 1 4 2 6 2.15 0.149 0.02403-0.00892.,Introduction to Abaqus/Standard and Abaqus/Explicit,L6.13,在 Abaqus/Standard中CONTACT规则,Message文件,Step 3,Increment 6:INCREMENT 6 STARTS.ATTEMPT NUMBER 1,TIME INCREMENT 1.266E-02 CONTACT PAIR(ASURF,BSURF)NODE 167 IS NOW SLIPPING.CONTACT PAIR(ASURF,BSURF)NODE 171
11、IS NOW SLIPPING.:CONTACT PAIR(ASURF,BSURF)NODE 153 OPENS.CONTACT PRESSURE/FORCE IS-845822.CONTACT PAIR(ASURF,BSURF)NODE 161 OPENS.CONTACT PRESSURE/FORCE IS-1.50656E+006.CONTACT PAIR(ASURF,BSURF)NODE 163 OPENS.CONTACT PRESSURE/FORCE IS-108355.CONTACT PAIR(ASURF,BSURF)NODE 165 OPENS.CONTACT PRESSURE/F
12、ORCE IS-620880.CONTACT PAIR(CSURF,DSURF)NODE 363 OPENS.CONTACT PRESSURE/FORCE IS-3.5893E+006.CONTACT PAIR(ESURF,FSURF)NODE 309 IS NOW SLIPPING.6 SEVERE DISCONTINUITIES OCCURRED DURING THIS ITERATION.5 POINTS CHANGED FROM CLOSED TO OPEN 1 POINTS CHANGED FROM STICKING TO SLIPPING,Introduction to Abaqu
13、s/Standard and Abaqus/Explicit,L6.14,在 Abaqus/Standard中CONTACT规则,Message文件,Step 3,Increment 6(contd):CONVERGENCE CHECKS FOR SEVERE DISCONTINUITY ITERATION 1 MAX.PENETRATION ERROR-8.16193E-009 AT NODE 331 OF CONTACT PAIR(ESURF,FSURF)MAX.CONTACT FORCE ERROR-4369.44 AT NODE 363 OF CONTACT PAIR(CSURF,DS
14、URF)THE ESTIMATED CONTACT FORCE ERROR IS LARGER THAN THE TIME-AVERAGED FORCE.AVERAGE FORCE 5.393E+03 TIME AVG.FORCE 3.147E+03 LARGEST RESIDUAL FORCE-1.110E+04 AT NODE 333 DOF 2 LARGEST INCREMENT OF DISP.-7.782E-04 AT NODE 329 DOF 2 LARGEST CORRECTION TO DISP.-1.737E-05 AT NODE 337 DOF 2 FORCE EQUILI
15、BRIUM NOT ACHIEVED WITHIN TOLERANCE.AVERAGE MOMENT 114.TIME AVG.MOMENT 89.8 ALL MOMENT RESIDUALS ARE ZERO LARGEST INCREMENT OF ROTATION 1.853E-33 AT NODE 100 DOF 6 LARGEST CORRECTION TO ROTATION 6.489E-34 AT NODE 300 DOF 6 THE MOMENT EQUILIBRIUM EQUATIONS HAVE CONVERGED,接触状态的收敛性检查,平衡的收敛性检查,不仅是接触的不相容
16、太大，而且是力的平衡也没有达到,Introduction to Abaqus/Standard and Abaqus/Explicit,L6.15,在 Abaqus/Standard中CONTACT规则,需要四次额外的迭代；前三次都是SDIs（包含接触不相容）。在最后的迭代中接触和平衡检查都通过，迭代收敛。CONVERGENCE CHECKS FOR SEVERE DISCONTINUITY ITERATION 2.CONVERGENCE CHECKS FOR SEVERE DISCONTINUITY ITERATION 3.CONVERGENCE CHECKS FOR SEVERE DISC
17、ONTINUITY ITERATION 4.CONVERGENCE CHECKS FOR EQUILIBRIUM ITERATION 1 MAX.PENETRATION ERROR-1.38869E-014 AT NODE 331 OF CONTACT PAIR(ESURF,FSURF)MAX.CONTACT FORCE ERROR-0.00111133 AT NODE 331 OF CONTACT PAIR(ESURF,FSURF)THE CONTACT CONSTRAINTS HAVE CONVERGED.AVERAGE FORCE 5.244E+03 TIME AVG.FORCE 3.1
18、23E+03 LARGEST RESIDUAL FORCE-9.24 AT NODE 367 DOF 1 LARGEST INCREMENT OF DISP.-7.809E-04 AT NODE 129 DOF 2 LARGEST CORRECTION TO DISP.4.229E-08 AT NODE 137 DOF 2 THE FORCE EQUILIBRIUM EQUATIONS HAVE CONVERGED AVERAGE MOMENT 109.TIME AVG.MOMENT 89.0 ALL MOMENT RESIDUALS ARE ZERO LARGEST INCREMENT OF
19、 ROTATION 1.925E-33 AT NODE 100 DOF 6 LARGEST CORRECTION TO ROTATION 2.049E-35 AT NODE 100 DOF 6 THE MOMENT EQUILIBRIUM RESPONSE WAS LINEAR IN THIS INCREMENT,No SDIs in this iteration,Introduction to Abaqus/Standard and Abaqus/Explicit,L6.16,在 Abaqus/Standard中CONTACT规则,增量摘要:ITERATION SUMMARY FOR THE
20、 INCREMENT:5 TOTAL ITERATIONS,OF WHICH 4 ARE SEVERE DISCONTINUITY ITERATIONS AND 1 ARE EQUILIBRIUM ITERATIONS.CURRENT VALUE OF MONITOR NODE 200 D.O.F.2 IS-3.028E-03 TIME INCREMENT COMPLETED 1.266E-02,FRACTION OF STEP COMPLETED 5.047E-02 STEP TIME COMPLETED 5.047E-02,TOTAL TIME COMPLETED 2.05,Introduction to Abaqus/Standard and Abaqus/Explicit,L6.17,在 Abaqus/Standard中CONTACT规则,Abaqus/Viewer中的接触诊断,Dassault Systmes,2008,习题5：密封圈接触,Introduction to Abaqus/Standard and Abaqus/Explicit,L6.19,习题5：密封圈接触,习题任务评估超弹材料模型定义面-面接触应用边界条件完成大位移分析显示结果,
