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1 – 2 of 2Junshan Hu, Xinyue Sun, Wei Tian, Shanyong Xuan, Yang Yan, Wang Changrui and Wenhe Liao
Aerospace assembly demands high drilling position accuracy for fastener holes. Hole position error correction is a key issue to meet the required hole position accuracy. This…
Abstract
Purpose
Aerospace assembly demands high drilling position accuracy for fastener holes. Hole position error correction is a key issue to meet the required hole position accuracy. This paper aims to propose a combined hole position error correction method to achieve high positioning accuracy.
Design/methodology/approach
The bilinear interpolation surface function based on the shape of the aerospace structure is capable of dealing with position error of non-gravity deformation. A gravity deformation model is developed based on mechanics theory to efficiently correct deformation error caused by gravity. Moreover, three solution strategies of the average, least-squares and genetic optimization algorithms are used to solve the coefficients in the gravity deformation model to further improve position accuracy and efficiency.
Findings
Experimental validation shows that the combined position error correction method proposed in this paper significantly reduces the position errors of fastener holes from 1.106 to 0.123 mm. The total position error is reduced by 43.49% compared with the traditional mechanics theory method.
Research limitations/implications
The position error correlation method could reach an accuracy of millimeter or submillimeter scale, which may not satisfy higher precision.
Practical implications
The proposed position error correction method has been integrated into the automatic drilling machine to ensure the drilling position accuracy.
Social implications
The proposed position error method could promote the wide application of automatic drilling and riveting machining system in aerospace industry.
Originality/value
A combined position error correction method and the complete roadmap for error compensation are proposed. The position accuracy of fastener holes is reduced stably below 0.2 mm, which can fulfill the requirements of aero-structural assembly.
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Keywords
Kai Zhang, Tingting Liu, Wenhe Liao, Changdong Zhang, Yishuai Yan and Daozhong Du
The purpose of this paper is to obtain high-performance ceramics and enrich additive manufacturing of ceramic parts. Also, a new manufacturing technique based on slurry by…
Abstract
Purpose
The purpose of this paper is to obtain high-performance ceramics and enrich additive manufacturing of ceramic parts. Also, a new manufacturing technique based on slurry by selective laser melting (SLM) was studied, which has some significant advantages compared to indirect selective laser sintering of ceramic powders.
Design/methodology/approach
To study the effect of laser parameters on the surface morphology and melting state of pure Al2O3 ceramics, laser power varied between 100 and 200 W and scan speed varied between 60 and 90 mm/s.
Findings
Experimental results show that Al2O3 slurry melts completely when the laser power is about 200 W and the scanning speed is 90 mm/s. Surface quality cannot be improved effectively by changing the scanning speed. However, surface quality improves when the laser power is 200∼205 W and energy density is 889∼911 J/mm3. Thermocapillary convection was observed during SLM. By changing the temperature gradient, streak convection and flowing Bénard cells were obtained during SLM of Al2O3 slurry.
Originality/value
It is feasible to produce slurry ceramic parts without binders through SLM. Increasing the laser power is the most effective way to fully melt the ceramics. Complex thermocapillary convection was observed during this new process; it may be used to produce crystals.
Details