Hello,

I am performing a monotonic pushover (displacement controlled) simulation on a steel shear wall assembly made of 10 instances. The instances are made up of S4R elements with a 20 mm mesh. Interaction is defined as surface-to-surface through contact pairs. In order to simulate screw connections, I defined mesh-independent fasteners at the screw locations and assigned them the connector property (MPC_PIN). Half way through the analysis, the .msg file reported the following warnings:

***WARNING: SOLVER PROBLEM. ZERO PIVOT WHEN PROCESSING ELEMENT 1126

(ASSEMBLY) INTERNAL NODE 175 D.O.F. 4

OVERCONSTRAINT CHECKS:

An overconstraint was detected at one of the Lagrange multipliers associated

with element 1126 ASSEMBLY_NAME ASSEMBLY. There are multiple constraints applied directly or chained

constraints that are applied indirectly to this element.

A list of nodes and chained constraints between these nodes that most likely lead to

the detected overconstraint can be printed out to the message file by including

*constraint controls, print=yes.

***WARNING: Solver problem. Zero pivot when processing D.O.F. 4 at one or more

of the internal nodes of 1 elements. The elements have been

identified in element set WarnElemSolvProbZeroPiv_4_1_89_1_1.

I rechecked the nodes as reported in the .msg file in the visualisation module and it only has one constrain definition (the point based fastener). So I edited the .inp file to print the constraint check using the following keywords:

*CONSTRAINT CONTROLS, PRINT=YES

I ran another analysis, however this time I got the following warning in the .dat file:

***WARNING: THE PRINT PARAMETER IS PERMITTED AS MODEL DATA ONLY. THIS

PARAMETER WILL BE IGNORED.

Am I missing something here? I was under the impression that adding the print=yes keyword would print a detailed list of the nodes and constrains that led to the zero pivot problem. Any help is greatly appreciated,

Thanks!