TOPress3D: An Educational MATLAB Code for 3D Topology Optimization with Design-Dependent Pressure Loads

Alapfogalmak

This paper introduces TOPress3D, an open-source MATLAB code for 3D topology optimization of structures subject to design-dependent pressure loads, aiming to provide an accessible and pedagogical tool for students, researchers, and newcomers in the field.

Kivonat

Bibliographic Information:

Kumar, P. (2024). TOPress3D: 3D topology optimization with design-dependent pressure loads in MATLAB. Optimization and Engineering. [Preprint]. https://arxiv.org/abs/2405.07733v2

Research Objective:

This paper introduces TOPress3D, a MATLAB code designed for performing 3D topology optimization on structures subjected to design-dependent fluidic pressure loads. The objective is to provide an accessible and pedagogical tool for newcomers, students, and researchers to learn and explore 3D topology optimization with design-dependent loads.

Methodology:

TOPress3D utilizes 3D hexahedral elements to parameterize design domains. It incorporates the 3D version of Darcy's law, including a drainage term, to model the relationship between pressure load and design variables. The method of moving asymptotes (MMA) is employed for updating design variables during optimization. The code is implemented in MATLAB and utilizes efficient assembly procedures for handling matrices.

Key Findings:

• TOPress3D provides a practical and accessible tool for 3D topology optimization with design-dependent pressure loads.
• The code is designed to be pedagogical, making it easy to understand and modify for various applications.
• TOPress3D employs efficient assembly procedures and utilizes the fsparse function for reduced memory requirements, enabling the solution of 3D problems on standard computers.
• The code's robustness and efficacy are demonstrated by solving four different design-dependent pressure load-bearing structures.

Main Conclusions:

TOPress3D offers a valuable resource for researchers and students interested in 3D topology optimization with design-dependent pressure loads. Its open-source nature and pedagogical approach encourage further exploration and application of the code in various engineering fields.

Significance:

This research contributes to the field of topology optimization by providing an accessible and efficient tool for handling design-dependent pressure loads in 3D structures. The availability of TOPress3D can potentially accelerate research and development in areas such as soft robotics, metamaterials, and other pressure-loaded structures.

Limitations and Future Research:

While TOPress3D provides a solid foundation, future research could focus on incorporating additional physical and geometrical constraints, such as buckling and stress, to address more complex engineering problems. Further development could also explore the integration of advanced optimization algorithms and parallel computing techniques to enhance the code's efficiency and scalability.

Statisztikák

The code is 158 lines long.
The code uses Kv = 1 and ϵ = 1 × 10−7 for the flow coefficients.
The penetration parameter ∆s is set equal to the size of a few finite elements.
The code utilizes a filter radius of √3 for the examples.
The maximum number of MMA iterations is set to 100 for the examples.

Idézetek

"While such loads are prevalent in various applications, addressing them within a topology optimization framework presents distinct challenges as they change direction, location and/or magnitude with design evolution."
"Therefore, availability of a publicly accessible pedagogical code can become particularly valuable and can serve as an educational tool and a practical entry point for newcomers, students, and researchers looking to familiarize themselves with this subject."
"TOPress3D is developed to fill the gap and accomplish the above mentioned objectives."

Főbb Kivonatok

TOPress3D: 3D topology optimization with design-dependent pressure loads in MATLAB

by Prabhat Kuma... : arxiv.org 10-07-2024

https://arxiv.org/pdf/2405.07733.pdf

Mélyebb kérdések

How can the principles of TOPress3D be extended to address fluid-structure interaction problems beyond pressure loading, such as those involving fluid flow and heat transfer?

TOPress3D, fundamentally built on the principles of topology optimization (TO) and finite element analysis (FEA), offers a solid foundation for extension into more complex fluid-structure interaction (FSI) problems. Here's how:

Incorporating Fluid Flow: Beyond static pressure, simulating fluid flow necessitates solving the Navier-Stokes equations. This could be achieved by:

Coupled Analysis: Integrating a computational fluid dynamics (CFD) solver with TOPress3D. The pressure field from CFD would act as a design-dependent load in the TO framework.
Streamline-Upwind Petrov-Galerkin (SUPG) Formulation: This FEA technique stabilizes solutions for convection-dominated flows, making it suitable for integration into TOPress3D.

Addressing Heat Transfer: Thermal effects introduce the need to solve the heat equation, potentially coupled with fluid flow.

Convection and Conduction: TOPress3D can be extended to include both conductive heat transfer within the structure and convective heat transfer at the fluid-structure interface.
Temperature-Dependent Material Properties: Realistic simulations might require incorporating the influence of temperature on material properties (e.g., Young's modulus) within the optimization.

Challenges and Considerations:

Computational Cost: Solving coupled FSI problems is computationally demanding, especially in 3D. Efficient numerical methods and parallel computing become crucial.
Meshing: Fluid-structure interfaces often require adaptive meshing techniques to accurately capture the evolving boundary.
Solver Coupling: Stable and accurate coupling between the TO, CFD, and heat transfer solvers is essential.

By addressing these aspects, the core principles of TOPress3D can be leveraged to tackle a broader range of FSI problems, leading to innovative designs optimized for complex multiphysics phenomena.

While TOPress3D focuses on compliance minimization, could alternative optimization objectives, such as maximizing stiffness or minimizing material usage under stress constraints, be incorporated into the code's framework?

Absolutely, the flexibility of the TOPress3D framework allows for the incorporation of alternative optimization objectives beyond compliance minimization. Here's how:

Maximizing Stiffness:

Objective Function: Instead of minimizing compliance (inverse of stiffness), the objective function can be directly set to maximize stiffness. This might involve maximizing the structure's fundamental frequency or minimizing the displacement under a given load.
Sensitivity Analysis: The adjoint-variable method used in TOPress3D can be adapted to derive sensitivities for the new stiffness-based objective function.

Minimizing Material Usage under Stress Constraints:

Objective Function: The objective function becomes minimizing the total volume of material used in the design.
Stress Constraints: Local stress constraints need to be added to ensure the structural integrity of the optimized design. These constraints can be implemented at the element level using various stress criteria (e.g., von Mises stress).
Sensitivity Analysis: Sensitivities of the stress constraints with respect to design variables need to be derived and incorporated into the optimization process.

Implementation in TOPress3D:

Modify Objective Function: The code section responsible for calculating the objective function (compliance in the original code) needs to be replaced with the new objective function.
Add Constraint Functions: Functions to evaluate the new constraints (e.g., stress constraints) need to be added.
Update Sensitivity Calculations: The sensitivity analysis section needs to be modified to include the derivatives of the new objective and constraint functions.

By implementing these modifications, TOPress3D can be readily adapted to address a wider range of design problems with different optimization goals, enhancing its versatility and applicability.

How can the insights gained from TOPress3D's optimized designs inform the development of novel manufacturing techniques or materials specifically tailored for pressure-loaded applications?

TOPress3D, by generating optimized designs for pressure-loaded structures, provides valuable insights that can drive innovation in manufacturing techniques and material development. Here's how:

Guiding Manufacturing Processes:

Additive Manufacturing (AM): The complex geometries often produced by TOPress3D are ideally suited for AM techniques like 3D printing. The software can generate designs specifically tailored for the capabilities and limitations of different AM processes.
Mold Design: For traditional manufacturing methods like injection molding, TOPress3D can aid in designing complex mold cavities that would be challenging to conceive manually.
Lightweighting Strategies: The optimized designs can inform the strategic placement of material to minimize weight while maintaining structural integrity under pressure, leading to more efficient use of resources.

Inspiring Material Development:

Functionally Graded Materials (FGMs): TOPress3D can be extended to incorporate FGMs, where material properties vary spatially. This allows for tailoring material properties to the specific stress and strain distributions predicted by the software.
Lattice Structures and Metamaterials: The software can guide the design of complex lattice structures or metamaterials with tailored mechanical properties, such as high strength-to-weight ratios or negative Poisson's ratios, suitable for pressure-loaded applications.
Bio-Inspired Designs: TOPress3D's ability to mimic natural structures optimized for pressure, like those found in plants or marine organisms, can inspire the development of new materials and fabrication techniques.

Bridging Design and Manufacturing:

Design for Manufacturing (DFM): By incorporating manufacturing constraints into the optimization process, TOPress3D can ensure that the generated designs are feasible to manufacture using available techniques.
Process Optimization: The software can be used to optimize not only the final design but also the manufacturing process itself, leading to reduced waste, improved efficiency, and enhanced product performance.

By fostering a tighter integration between design, material science, and manufacturing, the insights from TOPress3D can pave the way for next-generation pressure-loaded structures with enhanced performance, efficiency, and sustainability.