I presume you want to evaluate the stress/strain state in the pipe during installation over un-even terrain?

Here are the steps to do this:

• Model the pipe horizontally, with continuous "+Y" supports. Each "+Y" should have a corresponding CNODE.
• Displace the CNODES in the vertical direction an amount equal to the variation in elevation, from the elevation origin.
• Run the analysis.

If you're after "strain", recall that (epsilon = sigma / elastic modulus).


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Regards,
Richard Ay (COADE, Inc.)