topic Differential temperature primary stresses in Structural Bridge Design Forum

Differential temperature primary stresses

Anonymous — Tue, 19 Dec 2017 15:16:59 GMT

Hi,

I would like to know how the sofware determine the primary stresses and the relaxing forces fot the differential (Z) temperature.

I tried to find the same explanations that exisit for the differential shrinkage (where each fiber value are explains)

In my case, I have 2 dilatation coefficients very differents... that's why I want to check what is done.

Thanks.

Re: Differential temperature primary stresses

simon_hooper — Wed, 20 Dec 2017 21:56:03 GMT

Hi Gregory

The software calculates the differential temperature relaxing moments and forces by dividing each section element into a number of horizontal strips. The strain at the centroid of each strip is determined using the profile temperature at that height multiplied by the coefficient of expansion.

As noted in the help, if the top or bottom surface of the section is not horizontal, the calculations will not be realistic, and a simplified model of the section may be more appropriate.

Thanks

Simon

Re: Differential temperature primary stresses

Anonymous — Thu, 21 Dec 2017 07:23:00 GMT

Simon,

Thanks for your answer.

OK for me, I manually find same results in my particular case.

So I have : {N, M} and {epsilon, psi}

I wonder now how the software determine stresses along the beam (analytically like it is done for differential shrinkage)

Thank you again.

Re: Differential temperature primary stresses

Anonymous — Thu, 21 Dec 2017 17:49:21 GMT

Simon,

I finally manage to manually check the software results.

I think that the calculation details are usefull when click "RESULTS" (it seem only t be the "epsilon" and the "psi" associate to N & M)

Thanks again. I accept your response as solution and keep at disposal for who try to find this details.

G. PAJOT

Re: Differential temperature primary stresses

Anonymous — Sat, 23 Dec 2017 10:42:38 GMT

Hi Everyone,

Thanks for sharing the information.