Optimized Design of Structure of High-Bending-Rigidity Circular Tube

Shaoying Li,Zhongquan Qu

doi:10.3390/su13084534

Shaoying Li, Zhongquan Qu

Open Access

https://doi.org/10.3390/su13084534

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Abstract

Circular tubes are widely used in daily life and manufacture under bending load. The structural parameters of a circular tube, such as its wall thickness, number and shapes of ribs, and supporting flanges, are closely related to the tube’s bending rigidity. In this study, a tube with eight ribs and a flange was optimized, in order to obtain the lowest weight, through comprehensive structural optimization. We obtained the optimal structural parameters of the tube and the influence of the structural parameters on the tube’s weight. The structural parameters of tubes with different numbers of ribs were optimized. The tube with different number of ribs had the same inner diameter, bending load, and length as the tube with eight ribs. We conducted an experiment to verify the structural optimization simulation. Different tube sizes were subsequently optimized. The optimized tube with four trapezoidal ribs and a flange reduced the weight by more than 73% while maintaining the same deformation. The weight of the optimized tube with a flange reached a stable value after four trapezoidal ribs were added. When the number of ribs was two, the weight was the largest. The analysis results were consistent with the numerical results. A new AWATR (appropriate width and thickness of ribs can improve the bending rigidity of the tubes) formula was proposed, which can effectively improve the bending rigidity of tubes. Different shapes of tubes were optimized and compared. The optimized tube with four trapezoidal ribs and a flange was the lightest and easy to manufacture.

Highlights

Accepted: 15 April 2021Circular tubes are widely used as components in various applications, including buckets, columns for buildings, shafts, poles, and oil storage tanks
Jin et al built a finite element model to analyze the mechanical properties of tubes under combined axial compression and bending loads
It is urgent to combine the structural parameters reasonably to find the lightest structure under certain deformation

Summary

Introduction

Accepted: 15 April 2021Circular tubes are widely used as components in various applications, including buckets, columns for buildings, shafts, poles, and oil storage tanks. Many researchers have studied circular tubes, in an attempt to increase their strengths and lowering the associated waste by improving the structures of tubes [1,2,3,4,5,6,7]. Hui et al studied the behaviors of circular concrete filled double steel tubular slender columns and beams They established a finite element model, in which the parameters were hollow ratio, eccentric ratio, and material strength. Jin et al built a finite element model to analyze the mechanical properties of tubes under combined axial compression and bending loads They studied the effects of the diameter by thickness ratio and eccentricity by diameter ratio on the structure’s strength and buckling strain [9]

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