Reducing the size of parts, reducing the number of parts, and reducing the weight of parts is the relentless pursuit of aerospace, automobile manufacturing, and other fields. For example, every gram of aircraft weight reduction is equivalent to reducing a lot of fuel consumption during service. As another example, by reducing the size of the satellite's components, more space can be provided to increase the battery power, thereby increasing the time the satellite can stay in space.
It should be noted that lightweight is generally understood as the removal of material from a component or part in order to reduce its weight. This is what's happening, and it's why there's often an emphasis on "material reduction," or the replacement of some materials with other lightweight materials.
By choosing a material with a higher specific strength, the overall weight of the part can be reduced. For example, if we compare stainless steel, aluminum alloy, and titanium alloy, titanium alloy has a higher specific strength and can use less material to achieve the same performance level.
This focus on materials, therefore, influences part design that reflects how fundamental design changes can help minimize material consumption and ultimately reduce build time.
Since the lightweight of any structure will directly affect the mechanical properties of the parts, manufacturability is one of the most important factors affecting lightweight. You can have the lightest and highest-performance theoretical design, but if it cannot be manufactured, this design is useless. become useless.
Another important factor is the cost of the part. If the lightweight part is poorly designed using topology optimization, there will be additional costs in removing excessive support structures and adding surface treatments. On the other hand, printing dot matrix lattices and TPMS structures may increase the 3D printing time, leading to higher manufacturing costs of the part.
Manufacturers have been utilizing additive manufacturing for two decades, but it is only in recent years that 3D printing has seen advances in lightweight parts and established new software strategies for lightweight.
Topology Optimization and Generative Design
One of the frequently explored software strategies in terms of lightweight is topology optimization: The Topology Optimization capability, based on the finite element method (FEM) to optimize the material assignment of a part for stiffness or strength goals, enables part lightweight design. This design strategy optimizes the material layout within a given design space for a given set of loads, boundary conditions, and constraints.
In the market, Topology Optimization (Topology Optimization) and Generative Design (Generative Design) are usually confused in many cases, but after careful study, Generative Design (Generative Design) is based on some initial parameters through iteration and adjustment. Find an (optimized) model. Topology Optimization (Topology Optimization) is to analyze a given model. It is common to conduct finite element analysis based on boundary conditions, and then deform or delete the model to optimize it.
Generative Design is a process of human-computer interaction and self-innovation. According to the design intent of the inputter, through the "generative" system, the geometric model of the potentially feasible design plan is generated, and then comprehensively compared, and the selected design plan is pushed to the designer for the final decision.
Commonly understood, generative design is a design method that automatically generates artwork, architectural models, and product models through algorithms in design software. Generative design is a parametric modeling method. During the design process, after the designer inputs product parameters, the algorithm will automatically adjust and judge until the optimal design is obtained.
Lattice or TPMS-filled structure
Due to the advent of additive manufacturing techniques, periodic cellular structures, especially triple periodic minimal surfaces (TPMS), have attracted extensive research interest. A TPMS is essentially the smallest surface where the average curvature of all points is zero. The TPMS structure can be modeled mathematically and can be modeled repeatedly in three directions. This pattern allows TPMS cells to grow in three mutually perpendicular directions, forming a 3D array of TPMS cells.
TPMS is a triple periodic minimal surface (TPMS). For structural applications, the TPMS design exhibits a high strength-to-weight ratio. Used in conjunction with additive manufacturing techniques, it enables designers to create multifunctional structures with high strength and heat dissipation properties.
Filling structures with lattice lattices or TPMS are interesting approaches to explore in this regard, for example, the additive manufacturing software Cognitive Design has created a large database of such metamaterials and their mechanical properties. The Infill Optimizer, part of Cognitive Additive, intelligently places such structures based on stress paths, reducing overall weight without compromising mechanical performance.
Structural Integration
Structural integration is a strategy that requires solid expertise and the ability to integrate multiple parts into one. If properly designed, the part can provide improved functionality. For example, a few years ago, Airbus and 3D Systems developed the first airworthy metal 3D printed radio frequency (RF) filter, tested and validated for use in commercial telecommunications satellites.
Traditionally, RF filters are designed using standard components, such as rectangular cavities and waveguide cross-sections with vertical bends, whose shape and connections are determined by standard processes such as milling and EDM.
Typically, the cavity for an RF filter is machined in two parts that are bolted together, which not only adds weight but also adds an assembly step and an extra quality inspection process. Using CST MWS software, a 3D electromagnetic simulation tool, the 3D Systems team developed a recessed elliptical cavity to guide the RF current, a design that reduced production costs and reduced weight by 50%.
A new software solution based on artificial intelligence enables design engineers to "program" algorithms, and in this way, their designs evolve and develop into products of complex shapes that can be easily manufactured through additive manufacturing.
This trend will continue, arguably indefinitely, as software solutions continue to evolve. Just like the observation and analysis of "The Future of Artificial Intelligence and Design - 2017 Design and Artificial Intelligence Report" by Fan Ling of Tongji x Tezan Design and Artificial Intelligence Laboratory: The trend of extreme segmentation on the demand side needs to be matched by artificial intelligence on the supply side; The trend of online/connection/interaction has gradually developed from online information, online relationships, and online things to various skills online, and will eventually be online of heart and brain—artificial intelligence/AI; accompanied by irreplaceable Individuals with super-segmented skills will continue to emerge, and the era of mediocrity will end; the future organization will be a new organization of human/computer interaction, and they will flexibly assign tasks to external talents, internal talents, or machines to complete automatically. The mechanism integrates the entire design workflow to achieve the optimal task completion path.