Filling Lightweight Research on Pyramid Lattice with Small Slenderness Ratio Fabricated by SLM

doi:10.3901/JME.2021.24.132

Abstract

Abstract: Electro-hydrostatic actuator(EHA) is a highly integrated component in the motion control of aircraft. High ratio of power to weight requires extreme lightweight design for multiple components. However, due to small filling area and limited size, slenderness ratio of filling lattice rod is small. In order to solve the poor accuracy of Euler beam theory for short bars, the static performance of pyramid lattice are deduced with small slenderness ratio based on Timoshenko beam theory. Derived equations show that the equivalent elastic modulus of quadrangular pyramid lattice with small aspect ratio based on Timoshenko beam theory is inversely proportional to the square of aspect ratio, and the equivalent yield strength is proportional to the square of aspect ratio. In addition, in view of the anisotropy of the selective laser melting (SLM) process in laser forming direction, the anisotropy data of the yield strength with the overhang angle is obtained through static experiments, and this law is fitted into the performance characterization formula. The filling parameters of quadrangular pyramid lattice considering process constraints are obtained by size optimization. Selective laser melting is utilized to manufacture the lightweight casing. Compared results shows that the weight of EHA motor shell is reduced by nearly 200 g, accounting for 16.3% of original model.

Key words: selective laser melting, pyramid lattice, Timoshenko beam, filling lightweight

CLC Number:

TH122

LI Yongxin, GUO Changchun, LI Kailun, YU Tian. Filling Lightweight Research on Pyramid Lattice with Small Slenderness Ratio Fabricated by SLM[J]. Journal of Mechanical Engineering, 2021, 57(24): 132-138.

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