Optistruct/Compose MultiPhysics Optimization Using DRESP3

Hello,

My name is Muhammed Cakir. I am an optomechanical enginner working on TAI. 

I am trying to solve a multiphysics optimization problem using Optistruct. I need a technical support on the use DRESP3 command. The problem is defined below in more detail. 

Problem Statement: 

Size optimization is to be performed on an optical part by keeping the displacement of the optical surface nodes of the part in a certain limit. A special formulation is used to calculate "the displacement" of the surface nodes by an external matlab code (this is ready). Calculation of "the displacement" requires a complex calculation procedure incorporating the undeformed coordinates and the displacements of the surface nodes.

Optistruct should calculate the nodal displacement of the particular surface at every iteration of the optimization, then these displacement data should be used as DRESP3 to be fed to the Compose for further calculations on Matlab. At the best, at every iteration nodal displacements should be written on an excel file. But pch file is also okay.  

My problem is obtaining the nodal displacement and using this displacement data for making further calculations in Matlab over Compose. 

Please someone help me on this issue. 

Regards.