Design Optimization of Double-array Bolted Joints in Cylindrical Composite Structures

Kim, Myung-Jun; Kim, Yongha; Kim, Pyeunghwa; Park, Jungsun

doi:10.5139/ijass.2016.17.3.332

Cited by 4 publications

(4 citation statements)

References 9 publications

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“…1 *w 1 = −5.34 × 10 −3 t 3 + 2.40 × 10 −1 t 2 – 2.67t + 1. w 2 = −2.74 × 10 −5 t 3 + 2.24 x 10 −3 t 2 – 0.05t + 1. w 3 = 3.21 × 10 −5 t 3 – 1.62 x 10 −3 t 2 + 2.74t + 1. w 4 = 1.…”

Section: Cure Cycle Modificationmentioning

confidence: 99%

“…The demand for CFRPs has been constantly growing across aerospace, automotive, marine, and wind energy industries as the composite materials offer advantageous mechanical properties such as light weight, high specific strength/stiffness, fatigue life and improved corrosion resistance compared to conventional materials. [1][2][3][4] Traditionally, primary composite structures are manufactured using autoclaves (pressurized ovens), where prepregs-fiber bed reinforcements pre-impregnated with catalyzed yet uncured resin-are consolidated under high pressure and temperature.…”

Section: Introductionmentioning

confidence: 99%

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Cure cycle modification for efficient vacuum bag only prepreg process

Hyun

Kim

Shin

et al. 2020

Journal of Composite Materials

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Over the past decade, increasing use of continuous fiber-reinforced polymer composites has created a demand for manufacturing methods with lower costs, higher production rates, and improved processing efficiency. To meet the growing demands, vacuum bag only (VBO) prepreg processing has been proposed and implemented in industrial settings. However, in the absence of high consolidation pressure, VBO prepreg must undergo compaction for longer durations during cure and requires use of more elaborate processing schemes to conform to complex geometries. The main objective of our cure cycle modification was to reduce overall manufacturing time for more efficient processing, while maintaining robust part quality. This study demonstrates the effect of cure cycle on formability and part quality of three complex-shaped composite structures, a bulkhead, fuselage, and I section frame, featuring drop-offs, corners and sandwich areas consisting of less than 10 plies. Three different cure cycles were chosen: Reference cure cycle 1, Modified I and Modified II cure cycle. The reference was modified based on resin cure kinetics/viscosity modeling results and “effective flow number” to shorten the overall cure cycle time while maintaining robust part quality. To compare the quality of manufactured parts, destructive test and digestion method were used. For the bulkhead parts, Modified I was proven to be more effective in meeting the commercially acceptable part criteria (void content, ply wrinkle, resin ridge, and surface resin starvation), whereas Reference failed to meet the requirements, showing pervasive presence of porosity in drop-offs, corners and sandwich areas. The fuselage and I section frame parts produced with Modified I and Modified II were shown to meet the part quality requirements, with slight improvements in surface quality observed with the Modified II method.

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Section: Cure Cycle Modificationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Cure cycle modification for efficient vacuum bag only prepreg process

Hyun

Kim

Shin

et al. 2020

Journal of Composite Materials

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“…It was found that the bearing capacity was positively correlated with the bolt spacing in the transverse arrangement; while in the longitudinal arrangement, the bearing capacity was positively correlated with the edge distance, and weakly related to the end distance and the bolt spacing. Kim et al [7][8][9][10] Harnessed finite element methods in conjunction with numerical optimization to analyze the performance of diverse bolted connection scenarios. Their studies aimed to determine the optimal arrangement schemes and tightening sequences, with the overarching goal of maximizing the performance of bolted connections.…”

Section: Introductionmentioning

confidence: 99%

Rapid assembly bolt connection design method for TBM disc cutter box based on AHP

Sun,

Zhao,

Xiao

et al. 2024

Advances in Mechanical Engineering

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With the TBM disc cutter box as the subject of investigation, this study addresses the intricate and labor-intensive nature of the assembly process in TBM disc cutter box welding assembly. In order to expedite the assembly of the cutter-head and disc cutter box, an alternative approach utilizing combined bolt connections is implemented in place of welding assembly. Therefore, this article proposes a TBM disc cutter combination bolt connection design method based on AHP. Initially, a hierarchical analysis model is constructed, taking into account the actual conditions of the TBM disc cutter box combined bolt connections. Subsequently, from the array of factors influencing bolted connection performance, five experimental variables were chosen, and an orthogonal experimental layout was devised to examine the stress dispersion in the TBM disc cutter box under conditions of bolted assembly, employing finite element analysis. By conducting extreme difference analysis, the study examined the effects of each experimental factor on the bolt connection performance, and determined the order of importance of each factor more objectively. Thus, the comprehensive weights of each factor were calculated, and the optimal solution of the bolt connection scheme was selected by synthesizing the effects of multiple factors.

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“…Wang et al [11] carried out layout optimization experiments on bolt sets based on the firefly algorithm, and carried out simulation analysis on double-row bolts and three-row bolts, and the optimized bolt layout reduced the perimeter stress of the holes and improved the safety of the structure. However, the optimization of multi-bolt joint structures in the existing literature is limited to symmetric bolt structures [12][13][14][15][16], while there are few studies on asymmetric bolt structures, especially the optimization of a multi-bolt layout in a triangular position. In addition, researchers rarely apply the gray wolf optimization algorithm to the layout optimization of the connection structure of large complex equipment.…”

Section: Introductionmentioning

confidence: 99%

Triangular Position Multi-Bolt Layout Structure Optimization

Lu,

Zhu,

Liu

et al. 2023

Applied Sciences

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Stress concentration often occurs around bolt holes in load-bearing joint structures of large complex equipment, ships, aerospace and other complex machinery fields, which is an important mechanical factor leading to the failure of joint structures. It is of great engineering significance to study the phenomenon of stress concentration on connected structures for the safety of large and complex equipment; meanwhile, the layout of bolts seriously affects the stress around holes. Many scholars have studied the layout optimization of multi-bolted structures through experiments and simulations, but few algorithms have been applied to the layout optimization of bolted structures. And most of the studied types of multi-bolt structures are symmetrical. Therefore, in this paper, the gray wolf algorithm is used to optimize the layout of nickel steel plate connectors with a bolt layout in triangular position, and the optimal objective function is found based on the hole circumferential stress of the nickel steel plate, maximum shear stress of the bolt and bending stress of the nickel steel plate. Comparing the optimal values obtained by the fruit fly optimization algorithm, particle swarm optimization algorithm, gray wolf optimization algorithm, multiverse optimization algorithm and wind driven optimization algorithm, the accuracy of selecting the gray wolf algorithm for optimization is verified. A multi-bolt connection structure model was established in ABAQUS, and the surface stress before and after optimization was compared to verify the correctness of the gray wolf algorithm applied to the structure layout optimization of the nickel steel flat bolt connection. The results show that under the force of 15 KN, compared with the original bolt structure layout, the optimized upper side nickel steel plate bore peripheral stress is reduced by 73.1 MPa, and the optimization rate is 24%; bolt stress is reduced by 47.7 MPa, and the optimization rate is 12.5%; when the load is less than 18 KN, the optimization effect of both the upper nickel steel plate and bolt group is more than 10%. When the load is greater than 18 KN, the optimization effect is reduced, and when the load is greater than 21 KN, the nickel steel plate has exceeded the yield limit. Due to the existence of fixed constraints, the optimization of the lower nickel steel plate is not obvious. The results of this study can provide data and theoretical support for the layout optimization of the nickel steel flat bolt connection structure, and help to improve reliability analysis and health monitoring in complex assembly fields such as large complex equipment and aerospace.

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Design Optimization of Double-array Bolted Joints in Cylindrical Composite Structures

Cited by 4 publications

References 9 publications

Cure cycle modification for efficient vacuum bag only prepreg process

Cure cycle modification for efficient vacuum bag only prepreg process

Rapid assembly bolt connection design method for TBM disc cutter box based on AHP

Triangular Position Multi-Bolt Layout Structure Optimization

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