Modeling and Optimization of Bidirectional Clamping Forces in Drilling of Stacked Aluminum Alloy Plates.

Jintong Liu,Huiyue Dong,Anan Zhao,Piao Wan,Yunbo Bi

doi:10.3390/ma13122866

Abstract

Interlayer burrs formation during drilling of stacked plates is a common problem in the field of aircraft assembly. Burrs elimination requires extra deburring operations which is time-consuming and costly. An effective way to inhibit interlayer burrs is to reduce the interlayer gap by preloading clamping force. In this paper, based on the theory of plates and shells, a mathematical model of interlayer gap with bidirectional clamping forces was established. The relationship between the upper and lower clamping forces was investigated when the interlayer gap reaches zero. The optimization of the bidirectional clamping forces was performed to reduce the degree and non-uniformity of the deflections of the stacked plates. Then, the finite element simulation was conducted to verify the mathematical model. Finally, drilling experiments were carried out on 2024-T3 aluminum alloy stacked plates based on the dual-machine-based automatic drilling and riveting system. The experimental results show that the optimized bidirectional clamping forces can significantly reduce the burr heights. The work in this paper enables us to understand the effect of bidirectional clamping forces on the interlayer gap and paves the way for the practical application.

Highlights

Under the premise of satisfying the structural strength requirements, a primary pursuit for modern aircraft is to remain lightweight
To improve the drilling and connection quality of aircraft components, many automatic drilling and riveting systems are introduced into aircraft manufacturing industries [4,5,6]
During the automatic drilling process of stacked metal plates, one of the most outstanding issues is the formation of interlayer burr [7,8]

Summary

Introduction

Under the premise of satisfying the structural strength requirements, a primary pursuit for modern aircraft is to remain lightweight. The connection quality of lightweight stacked structures directly affects the fatigue performance and service life of the aircraft. During the automatic drilling process of stacked metal plates, one of the most outstanding issues is the formation of interlayer burr [7,8]. The existence of interlayer burr affects the hole quality and leads to connection decline or even failure [9]. After completing the drilling process, the deburring operation has to be performed to eliminate the interlayer burrs. The stacked plates need to be disassembled and reassembled several times. These extra operations are time-consuming and affect the assembly precision [10,11]

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Results

Conclusion