When I use expansion in analysis below error message is displayed

Hi

I used coupled temperature displacement analysis in Abaqus for simulation hot forming sheet.

obtain negative temperature in coupled temperature displacement analysis in Abaqus.

When I use expansion in analysis  below error message is displayed

The Abaqus time increment has become negative?? = -3.60330E-07

The ratio of deformation speed to wave speed exceeds 1.0000 in at least one element. This usually indicates an error with the model definition. Additional diagnostic information may be found in the message file 

my step type: Dynamic, Temp-disp, Explicit 

mesh type: S4RT

contact type: surface to surface(Explicit) Penalty method contact  with termal conductance

Please help me to solve this problem.