A review of shape memory alloy research, applications and opportunities

https://spiral.imperial.ac.uk/bitstream/10044/1/73026/9/1-s2.0-S0264127519306021-main.pdf

Review on design and structural optimisation in additive manufacturing: Towards next-generation lightweight structures

Cellular structures are made up of an interconnected network of plates, struts, or small unit cells and acquire many unique benefits such as, high strength-to-weight ratio, excellent energy absorption, and minimizing material requirements. When compared with the complicated conventional processes, additive manufacturing (AM) technology is capable of fabricating geometries in almost all types of shapes, even with the small cellular structures inside, by adding material layer-by-layer directly from the digital data file. All major industries have been exploiting the benefits of cellular structures due to their prevalence over a wide range of research fields. To date, there are a few state-of-the-art reviews compiled focusing on a specific area of lattice structures, but many aspects still need to be reviewed. Therefore, this paper aims to provide a comprehensive review of the various lattice morphologies, design, and the AM of the cellular structures. Furthermore, the superior properties of the additively fabricated structure, as well as the applications and challenges, are presented. The conducted review has identified the significant limitations and gaps in the existing literature and has highlighted the areas that need further research in the design, optimization, characteristics, and applications, and the AM of the cellular structures. This review would provide a more precise understanding and the state-of-the-art of AM with the cellular structures for engineers and researchers in both academia and industrial applications.

A state-of-the-art review on types, design, optimization, and additive manufacturing of cellular structures

Industry 4.0 refers to the integration of a multiplicity of technologies and agents for the common goal of improving the efficiency and responsiveness of a production system. This integration has the potential to revolutionize the manner in which business are planned and conducted. Smart Manufacturing represents the implementation of Industry 4.0 on the manufacturing floor. The Internet of Things, Big Data, Cyber Physical Systems, Machine Learning, Additive Manufacturing, and Robotics are only some of the elements that are associated with this revolution. This article discusses trends in some of the habilitating technologies of Industry 4.0.

A brief discussion on the trends of habilitating technologies for Industry 4.0 and Smart manufacturing

Fundamentals of the fluid mechanics

Variation and consistency of Young’s modulus in steel

A methodology, which consists of design, optimization and evaluation of periodic lattice-based cellular structures fabricated by additive manufacturing, is presented. A user-friendly design framework for lattice cellular structures is developed by using a size optimization algorithm. A 3D modeling process for the lattice-based cellular structures is introduced for non-linear finite element analysis and production. The approach is demonstrated on compression block with periodic lattice-based unit cells. First, based on loading condition, most appropriate lattice layout is selected. Then, for the selected lattice layout, the lattice components are modeled as simple beam and size of the beam cross sections is optimized using in-house optimization approach for both yield and local buckling criteria. The 3D model for the optimized lattice structure is built and non-linear finite element study is conducted to predict the performance. Physical parts are 3D printed and tested to compare with the simulatio...

/pdf/design-and-fabrication-of-periodic-lattice-based-cellular-17d7stfdj1.pdf

Design and fabrication of periodic lattice-based cellular structures

Purpose




Methods to optimize lattice structure design, such as ground structure optimization, have been shown to be useful when generating efficient design concepts with complex truss-like cellular structures. Unfortunately, designs suggested by lattice structure optimization methods are often infeasible because the obtained cross-sectional parameter values cannot be fabricated by additive manufacturing (AM) processes, and it is often very difficult to transform a design proposal into one that can be additively designed. This paper aims to propose an improved, two-phase lattice structure optimization framework that considers manufacturing constraints for the AM process.




Design/methodology/approach




The proposed framework uses a conventional ground structure optimization method in the first phase. In the second phase, the results from the ground structure optimization are modified according to the pre-determined manufacturing constraints using a second optimization procedure. To decrease the computational cost of the optimization process, an efficient gradient-based optimization algorithm, namely, the method of feasible directions (MFDs), is integrated into this framework. The developed framework is applied to three different design examples. The efficacy of the framework is compared to that of existing lattice structure optimization methods.




Findings




The proposed optimization framework provided designs more efficiently and with better performance than the existing optimization methods.




Practical implications




The proposed framework can be used effectively for optimizing complex lattice-based structures.




Originality/value




An improved optimization framework that efficiently considers the AM constraints was reported for the design of lattice-based structures.

An improved lattice structure design optimization framework considering additive manufacturing constraints

An automotive vehicle door is provided including a first generally rigid outer structure having first and second ends; a second generally rigid inner structure with a major portion spaced from the first outer structure, the second inner structure having first and second ends generally positionally aligned with the first and second ends of the first outer structure, the second inner structure having an opening; a trim panel positioned generally adjacent the second inner structure; a target position in alignment with the opening of the second inner structure adjacent a first end of the second inner structure, the target also having a portion adjacent the first outer structure; and a beam having a first end generally fixed with respect to the second inner structure first end and a second end fixed with respect to the second inner structure second end, the beam crossing over the target and wherein an impact on the door first outer structure causes the target to move inwardly through the opening, contacting the beam between the beam first and second ends to force the beam second end to dislodge the trim panel from the second inner panel end and move the trim panel inwardly.

Umesh N. Gandhi

Papers

Variation and consistency of Young’s modulus in steel

Design and fabrication of periodic lattice-based cellular structures

An improved lattice structure design optimization framework considering additive manufacturing constraints

Push-out vehicle side door

Data-based approach in modeling automobile crash