| 590 | } |
| 591 | |
| 592 | void ShearPanelMaterial::SetEnvelope(void) |
| 593 | { |
| 594 | double kPos = stress1p/strain1p; |
| 595 | double kNeg = stress1n/strain1n; |
| 596 | double k = (kPos>kNeg) ? kPos:kNeg; |
| 597 | double u = (strain1p>-strain1n) ? 1e-4*strain1p:-1e-4*strain1n; |
| 598 | |
| 599 | envlpPosStrain(0) = u; |
| 600 | envlpPosStress(0) = u*k; |
| 601 | envlpNegStrain(0) = -u; |
| 602 | envlpNegStress(0) = -u*k; |
| 603 | |
| 604 | envlpPosStrain(1) = strain1p; |
| 605 | envlpPosStrain(2) = strain2p; |
| 606 | envlpPosStrain(3) = strain3p; |
| 607 | envlpPosStrain(4) = strain4p; |
| 608 | |
| 609 | envlpNegStrain(1) = strain1n; |
| 610 | envlpNegStrain(2) = strain2n; |
| 611 | envlpNegStrain(3) = strain3n; |
| 612 | envlpNegStrain(4) = strain4n; |
| 613 | |
| 614 | envlpPosStress(1) = stress1p; |
| 615 | envlpPosStress(2) = stress2p; |
| 616 | envlpPosStress(3) = stress3p; |
| 617 | envlpPosStress(4) = stress4p; |
| 618 | |
| 619 | envlpNegStress(1) = stress1n; |
| 620 | envlpNegStress(2) = stress2n; |
| 621 | envlpNegStress(3) = stress3n; |
| 622 | envlpNegStress(4) = stress4n; |
| 623 | |
| 624 | double k1 = (stress4p - stress3p)/(strain4p - strain3p); |
| 625 | double k2 = (stress4n - stress3n)/(strain4n - strain3n); |
| 626 | |
| 627 | |
| 628 | envlpPosStrain(5) = 1e+6*strain4p; |
| 629 | envlpPosStress(5) = (k1>0.0)? stress4p+k1*(envlpPosStrain(5) - strain4p):stress4p*1.1; |
| 630 | envlpNegStrain(5) = 1e+6*strain4n; |
| 631 | envlpNegStress(5) = (k2>0.0)? stress4n+k2*(envlpNegStrain(5) - strain4n):stress4n*1.1; |
| 632 | |
| 633 | // define critical material properties |
| 634 | kElasticPos = envlpPosStress(1)/envlpPosStrain(1); |
| 635 | kElasticNeg = envlpNegStress(1)/envlpNegStrain(1); |
| 636 | |
| 637 | double energypos = 0.5*envlpPosStrain(0)*envlpPosStress(0); |
| 638 | |
| 639 | for (int jt = 0; jt<4; jt++){ |
| 640 | energypos += 0.5*(envlpPosStress(jt) + envlpPosStress(jt+1))*(envlpPosStrain(jt+1)-envlpPosStrain(jt)); |
| 641 | } |
| 642 | |
| 643 | double energyneg = 0.5*envlpNegStrain(0)*envlpNegStress(0); |
| 644 | |
| 645 | for (int jy = 0; jy<4; jy++){ |
| 646 | energyneg += 0.5*(envlpNegStress(jy) + envlpNegStress(jy+1))*(envlpNegStrain(jy+1)-envlpNegStrain(jy)); |
| 647 | } |
| 648 | |
| 649 | double max_energy = (energypos>energyneg) ? energypos:energyneg; |