Combined truss and continuum topology optimization of structures.

Area of Science:

• Structural optimization
• Mechanical engineering
• Computational design

Background:

• Truss layout optimization excels in low volume fraction problems.
• Continuum topology optimization is suitable for medium to high volume fraction problems.
• Real-world designs often require a mix of both low and high volume fraction regions.

Purpose of the Study:

• To develop a hybrid optimization approach for structures with mixed volume fractions.
• To integrate truss layout and continuum topology optimization methods.
• To address limitations of individual optimization techniques in complex design scenarios.

Main Methods:

• A two-step hybrid optimization strategy is proposed.
• Identification of distinct low and high volume fraction regions within a design domain.
• Populating identified regions with truss and continuum elements, respectively, connected by interfaces.
• Utilizing a conic optimization formulation solvable by interior point solvers.

Main Results:

• The hybrid approach successfully identifies structures with mixed length scales.
• Demonstrated capability to incorporate both bulk continuum regions and fine truss elements.
• Numerical examples validate the efficacy of the proposed method.

Conclusions:

• The hybrid optimization approach effectively addresses designs with mixed volume fractions.
• This method offers a unified framework for integrating different structural optimization techniques.
• The approach enables the creation of complex, multi-scale structures efficiently.