Thermal-displacement coupled analysis UMAT

Dear all,

I am doing a sequentially coupled thermal-displacement analysis. an ODB file is used as prefiled to define thermal load and then a UMAT is used.

My question is how to generate DSTRAN with TEMP (coefficient of expansion is known）
My code is the following, but i think it does not work.

DO K1=1,NTENS
DSTRAN(K1)=(TEMP-LASTEMP)*0.00108
END DO

LASTEMP is temperature of last step.

0.00108 is coefficient of thermal expansion

Best regards