# Pinching4MaterialExample

The example files (RCyclicPinch.tcl,procUniaxialPinching.tcl, procRCycDAns.tcl) create a one-dimensional structural model consisting of a single truss element of length 1.0 and area 1.0 (Figure 1). The Pinching4 uniaxial material model is used to simulate the stress-strain response of the truss material. The truss is subjected to a pseudo-static cyclic loading. Several files are provided that include different input parameters for the Pinching4 material model and result in different load-displacement histories for the truss structure. Refer to the documentation about the Pinching4 uniaxial material model for additional information.

Pinching4ExampleA.jpg

Lines should be commented out as necessary within RCyclicPinch.tcl to exercise different degradation models of the Pinching4 uniaxial material model and different load histories.

If the structure is subjected to a monotonic load history, the load-displacement history is shown in Figure below results with the actual response history depending on the envelope chosen for the material model.

Pinching4ExampleB.jpg

If the structure is subjected to a cyclic load history:

Pinching4ExampleC.jpg

one of the load-displacement histories shown below results, with the exact response depending on the strength and stiffness degradation model employed.

Pinching4ExampleD.jpg

In this case the damage type activated was "Energy". The case in which the damage type activated was "Cycle" is shown below:

Pinching4ExampleE.jpg