Saurabh Patil
Ansys Employee

Hi John

Based on the context provided, it seems like the error you're encountering is related to the setup of your optimization constraints in ANSYS. In ANSYS, for Mass, Volume, Center of Gravity, or Moment of Inertia Response constraints, it is recommended to use Criterion objects in Measures object (inserted from Model Object).

The document titled "ANSYS Mechanical: Lighter & Stronger Structural Designs with Topology Optimization" provides a detailed explanation of how to set up a topology optimization analysis in ANSYS Mechanical. It mentions that the topology optimization analysis automatically defines certain properties and inserts default objects such as the optimization region, response constraint, and objective objects. The response constraint object specifies the optimization constraints. For this problem, the percentage of mass to retain on the design region. The objective object defines topology optimization goals [1].

The document titled "Plate With a Hole Optimization - ANSYS Innovation Courses" also provides a practical example of how to set up an optimization problem in ANSYS. It discusses how to define design variables, objective functions, and constraints [2].

Lastly, the document titled "Optimization Technologies in ANSYS" provides a comprehensive overview of the optimization strategies and technologies available in ANSYS. It mentions that ANSYS allows for both shape and topology optimizations and provides two optimization strategies: parameter-based optimization and parameter-free optimization [3].

I would recommend revisiting your setup and ensuring that your constraints are defined correctly according to the guidelines provided in these documents.

[1] Title: "ANSYS Mechanical: Lighter & Stronger Structural Designs with Topology Optimization", URL:
[2] Title: "Plate With a Hole Optimization - ANSYS Innovation Courses", URL:
[3] Title: "Optimization Technologies in ANSYS", URL: