When I use the Bond_SP01 command, one warning is prompted saying input unit systems are in kips and in. But I use SI system for the whole modelling. How I use that command?
Bond_SP01 command
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Bond_SP01 command
When I use the Bond_SP01 command, one warning is prompted saying input unit systems are in kips and in. But I use SI system for the whole modelling. How I use that command?
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hrodrigues
- Posts: 44
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- Location: Aveiro
- Contact:
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hrodrigues
- Posts: 44
- Joined: Wed Nov 14, 2007 7:50 am
- Location: Aveiro
- Contact:
ok
tkx
i was looking to the authors page and found the answer. (http://www.uwm.edu/%7Ejzhao/Bond_SP01_p ... ml#compile)
tkx anyway
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I use SI system throughout the modeling. But in your module, input system is in US system. Please suggest how I use your module?
A: The equations for bond_Sp01 uses the normalized slips, hence the unit has no effect on the shape of the model curves. You need six parameters (Fy, Sy, Fu, Su, b, and Rc) to define the bond_SP01 material model in the latest version of OpenSees. Among these parameters, factor b is initial harding ratio and Rc is pinching factor (both are unitless). The ultimate slip currently is set to be dependent on the yield slip. Hence, all you need to do is to obtain Sy the yield slip. The equation in the current ACI paper is in SI units as required by ACI, you would have to use Pa for fc' in the equation to get the correct Sy in mm. Some changes have been made to the equation such that the equations in Si units and English units can be converted using unit conversion. These equations will be included in the opensees manual and the ACI paper.
Q: This units thing is a mess!!!
A: use ksi for Fy and Fu in the model parameter. Use psi in the equation for Sy. The reason for have a different set of units in the equation for Sy is to have unit conversion correct and viable and Fy/square root of Fc' unitless in the equation.
tkx
i was looking to the authors page and found the answer. (http://www.uwm.edu/%7Ejzhao/Bond_SP01_p ... ml#compile)
tkx anyway
_______
I use SI system throughout the modeling. But in your module, input system is in US system. Please suggest how I use your module?
A: The equations for bond_Sp01 uses the normalized slips, hence the unit has no effect on the shape of the model curves. You need six parameters (Fy, Sy, Fu, Su, b, and Rc) to define the bond_SP01 material model in the latest version of OpenSees. Among these parameters, factor b is initial harding ratio and Rc is pinching factor (both are unitless). The ultimate slip currently is set to be dependent on the yield slip. Hence, all you need to do is to obtain Sy the yield slip. The equation in the current ACI paper is in SI units as required by ACI, you would have to use Pa for fc' in the equation to get the correct Sy in mm. Some changes have been made to the equation such that the equations in Si units and English units can be converted using unit conversion. These equations will be included in the opensees manual and the ACI paper.
Q: This units thing is a mess!!!
A: use ksi for Fy and Fu in the model parameter. Use psi in the equation for Sy. The reason for have a different set of units in the equation for Sy is to have unit conversion correct and viable and Fy/square root of Fc' unitless in the equation.