80,253 research outputs found
Recommended from our members
Design for Additive Manufacturing: A Method to Explore Unexplored Regions of the Design Space
Additive Manufacturing (AM) technologies enable the fabrication of parts and devices that
are geometrically complex, have graded material compositions, and can be customized. To take
advantage of these capabilities, it is important to assist designers in exploring unexplored regions
of design spaces. We present a Design for Additive Manufacturing (DFAM) method that
encompasses conceptual design, process selection, later design stages, and design for
manufacturing. The method is based on the process-structure-property-behavior model that is
common in the materials design literature. A prototype CAD system is presented that embodies
the method. Manufacturable ELements (MELs) are proposed as an intermediate representation
for supporting the manufacturing related aspects of the method. Examples of cellular materials
are used to illustrate the DFAM method.Mechanical Engineerin
Functionally gradient tissue scaffold design and deposition path planning for bio-additive processes
A layer-based tissue scaffold is designed with heterogeneous internal architecture. The proposed layer-based design uses a bi-layer pattern of radial and spiral layer consecutively to generate functionally gradient porosity following the geometry of the scaffold. Medial region is constructed from medial axis and used as an internal geometric feature for each layer. The radial layers are generated with sub-region channels by connecting the boundaries of the medial region and the layer’s outer contour. Proper connections with allowable geometric properties are ensured by applying optimization algorithms. Iso-porosity regions are determined by dividing the sub-regions into pore cells. The combination of consecutive layers generates the pore cells with desired pore sizes. To ensure the fabrication of the designed scaffolds, both contours have been optimized for a continuous, interconnected, and smooth deposition path-planning. The proposed methodologies can generate the structure with gradient (linear or non-linear), variational or constant porosity that can provide localized control of variational porosity along the scaffold architecture. The designed porous structures can be fabricated using bio-additive fabrication processes
Multiscale, thermomechanical topology optimization of self-supporting cellular structures for porous injection molds
Purpose
This paper aims to establish a multiscale topology optimization method for the optimal design of non-periodic, self-supporting cellular structures subjected to thermo-mechanical loads. The result is a hierarchically complex design that is thermally efficient, mechanically stable and suitable for additive manufacturing (AM).
Design/methodology/approach
The proposed method seeks to maximize thermo-mechanical performance at the macroscale in a conceptual design while obtaining maximum shear modulus for each unit cell at the mesoscale. Then, the macroscale performance is re-estimated, and the mesoscale design is updated until the macroscale performance is satisfied.
Findings
A two-dimensional Messerschmitt Bolkow Bolhm (MBB) beam withstanding thermo-mechanical load is presented to illustrate the proposed design method. Furthermore, the method is implemented to optimize a three-dimensional injection mold, which is successfully prototyped using 420 stainless steel infiltrated with bronze.
Originality/value
By developing a computationally efficient and manufacturing friendly inverse homogenization approach, the novel multiscale design could generate porous molds which can save up to 30 per cent material compared to their solid counterpart without decreasing thermo-mechanical performance.
Practical implications
This study is a useful tool for the designer in molding industries to reduce the cost of the injection mold and take full advantage of AM
- …