The proper treatment of 1d slidelines was added to implicit mechanics in LS971 Dev v. 85434. 11/16/13 Prior to this proper implementation, the contact was not implemented via the stiffness matrix and you'd get this warning... *** Warning 60046 (IMP+46) ********************************************************* * * * - WARNING - * * * * The implicit solution phase * * does not support the feature: * * 1D Slidelines * * * ********************************************************* _______________________________________________________________ *database_nodal_force_group + *database_nodfor as in pullbar.k should pick up the 1D contact forces. But understand it also picks up any other external forces on the nodes in the nodal force group. ___________________________________________________________ From the expression for shear force at time n+1 in the Users Manual, there is a plastic cap on the force equal to GB * As * umax. This cap decays according to EXP via umax. http://ftp.lstc.com/anonymous/outgoing/support/FAQ_kw/concrete/pullbar.k illustrates no decay in the rebar force when EXP=0 and noticeable decay in the rebar force when EXP = 3.0. Please understand that I chose input values of GB, SMAX, and EXP randomly for purposes of illustration only. I'm sorry. I don't have any values backed up by experimental data. GB * As * slip strain = force. Thus GB has units of stress. SMAX has units of strain (length per length), i.e., it's nondimensional. The parameter As is the rebar surface area = 2*pi*radius*length. du and umax are nondimensional "slip strains". The 1D contact in LS-DYNA follows that from LLNL DYNA3D. There is a little bit more discussion of 1D contact in the DYNA3D manual (1993). It's possible that documentation is available online... I haven't looked. The Users Manual doesn't indicate how SIGC, i.e., fc', is used. From the source code, it seems the expression for maximum allowable slip strain is actually umax = SMAX * [ 1 + 1.5(p/SIGC)^2 ] * e^(-EXP*D) p is the hydrostatic pressure in the material on the master (solid) side of the contact.