Zero Pivot solver problem when using full integration but no warning with reduced intgration
I am using UMAT and UEXTERNALDB for damage modeling of material. With the same geometry when I am employing full integration I am getting the following message.
***WARNING: SOLVER PROBLEM. ZERO PIVOT WHEN PROCESSING NODE 1 INSTANCE PART-1-1 D.O.F. 1
But when using reduced integration I am not getting any warning or error message.
Is there any possible reason for this type of warning message? What could be a possible remedy to identify the problem when writing a used-defined code like UMAT?