Zefeng Xiao

Structural optimization design for antenna bracket manufactured by selective laser melting

This paper aims to summarize design rules based on the process characteristics of selective laser melting (SLM) and structural optimization and apply the design rules in the lightweight design of an aluminum alloy antenna bracket. The design goal is to reduce 30 per cent of the weight while maintaining the stress levels in the original part.,To reduce weight as much as possible, the titanium alloy with higher specific strength was selected during the process of optimization. The material distribution of the bracket was improved by the topology optimization design. The redesign for SLM was used to obtain an optimization model, which was more suitable for SLM. The component performance was improved by shape optimization. The modal analysis data of the structural optimization model were compared with those of the stochastic lightweight model to verify the structural optimization model. The scanning data were compared with those of the original model to verify whether the model was suitable for SLM.,Structural optimization design for antenna bracket realized the mass decrease of 30.43 per cent and the fundamental frequency increase of 50.18 per cent. The modal analysis data of the stochastic lightweight model and the structural optimization model indicated that the optimization performance of structural optimization method was better than that of the stochastic lightweight method. The comparison results between the scanning data of the forming part and the original data confirmed that the structural optimization design for SLM lightweight component could achieve the desired forming accuracy.,This paper summarizes geometric constraints in SLM and derives design rules of structural optimization based on the process characteristics of SLM. SLM design rules make structural optimization design more reasonable. The combination of structural optimization design and SLM can improve the performance of lightweight antenna bracket significantly.

Effect of energy input on the UHMWPE fabricating process by selective laser sintering

Purpose This study aims to achieve customized prosthesis for total joint arthroplasty and total hip arthroplasty. Selective laser sintering (SLS) as additive manufacturing could enable small-scale fabrication of customized Ultra High Molecular Weight Polyethylene (UHMWPE) components; however, the processes for SLS of UHMWPE need to be improved. Design/methodology/approach This paper begins by improving the preheating system of the SLS fabricating equipment and then fabricating cuboids with the same size and cuboids with same volume and different size to study the warpage, demonstrating the effect of the value and uniformity of the preheating temperature on component fabrication. Warpage, density and tensile properties are investigated from the perspective of energy input density. Finally, complicated industrial parts are produced effectively by using optimized technological parameters. Findings The results show that components can be fabricated effectively after the optimization of the SLS technological parameters i.e. the preheating temperature the laser power the scanning interval and the scanning speed. The resulting warpage was found to be less than 0.1 mm along with the density as 83.25 and the tensile strength up to 14.1 Mpa. UHMWPE sample parts with good appearance and strength are obtained after ascertaining the effect of each factor on the fabrication of the sample parts. Originality/value It is very challenging to fabricate UHMWPE sample parts by SLS. This is a new step in the fabrication of customized UHMWPE sample parts.

Design and direct manufacture of non-assembly abacus by Selective Laser Melting

Selective Laser Melting (SLM), as an additive manufacturing technology, can directly manufacture desired functional metal parts. With the ability to freeform manufacture, SLM has had breakthroughs on design and manufacture compared with traditional methods. SLM apparatus in Dimetal series, DiMetal-100 developed by SCUT research group, has been used to study non-assembly mechanism. Taking copper cash abacus and collapsible abacus as examples, this article had studied the design rules and the key points to manufacture the non-assembly mechanism based on the SLM. An investigation into the capability of SLM technology, such as the geometric features resolution, critical incline angle, provided theoretical basis for designing the clearance of the joint and manufacturing direction of non-assembly mechanism. Then, the experiment of manufacturing copper cash abacus and collapsible abacus were conducted. The results proved that non-assembly mechanism can be well manufactured by SLM. This study provides basis for designing and manufacturing of creative non-assembly mechanism based on SLM technique.

Direct Manufacture of Non-Assembly Mechanism by Selective Laser Melting

Mechanism that is designed and assembled digitally and lately manufactured directly without post-assembly is called non-assembly mechanism. Selective Laser Melting(SLM) is a desirable technology for manufacturing non-assembly mechanisms directly as it can make complex functional parts directly. The critical factors of manufacturing non-assembly mechanisms by SLM such as display strategy and dimensional accuracy of clearance character are investigated in this paper. Non-assembly mechanisms such as Copper Cash Abacus and Collapsible Abacus, planar linkages (slider-crank, crank-rocker, rocker-slider) and universal joint, etc are freely designed and are manufactured by DiMetal-100 series SLM equipment. It is shown that SLM can not only manufacture parts with complex structures successfully, but also can manufacture nonassembly mechanisms with motion performance directly. It provides a feasible method for the digital design and integrated fabrication of mechanical and electronic products.