Numerical simulation of double-bag progressive compression method of resin delivery in liquid composite moulding

Chang, C.-S.

doi:10.1080/14658011.2019.1647387

Cited by 4 publications

(2 citation statements)

References 39 publications

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“…Wagner et al [11] presented a numerical design approach based on the reduced stiffness method for the buckling of shell structures. Although a lot of effort has gone into developing novel manufacturing and the production of composites [15][16][17][18], there has been no investigation into the KDF of composite tubes. Thus, the aim of the current study was to investigate the KDF over a large range of a r/t through buckling tests with r = 100 mm, t = 0.112 mm, and r/t = 893.…”

Section: Introductionmentioning

confidence: 99%

Buckling Test of Composite Cylindrical Shells with Large Radius Thickness Ratio

et al. 2021

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A buckling test of composite cylindrical shells with a radius–thickness ratio (r/t) = 893 under axial compression was conducted to investigate the effects of the radius–thickness ratio (r/t). It is known that the buckling load of cylinders shows large differences and scatter between theory and experiment. The ratio of the experimental buckling load and theoretical buckling load is called the knockdown factor (KDF). Many investigations have been conducted to find the cause of the degradation and scatter in the KDF, but as yet, no cause has been found. In 1968, NASA’s buckling design criterion, NASA SP-8007, gave an empirical KDF curve that decreased with the increasing r/t (up to 2000) for metal cylinders. The same curve has been applied to composite cylinders. Recently, Takano derived a flat lower-bound KDF in terms of A- and B-basis values (99% and 90% probability with a 95% confidence level) through a statistical analysis of experimental buckling loads. The result, however, based on experimental results up to r/t = 500 and, thus, the dependency on a large range of r/t, is not clear. Thus, the authors focused on a larger range of r/t. Cylindrical shells made from carbon fiber-reinforced plastic (CFRP) were tested. The nominal radius, thickness, and length were r = 100.118 mm, t = 0.118 mm, and L = 200 mm and, thus, the r/t = 848 and length-to-radius ratio (L/r) = 2.0. Shape imperfections were also measured by using in-house laser displacement equipment. The buckling load was slightly affected by the r/t, but the reduction in the KDF was insignificant.

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Section: Introductionmentioning

confidence: 99%

Buckling Test of Composite Cylindrical Shells with Large Radius Thickness Ratio

et al. 2021

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“…[2][3][4] These fittings, however, cannot be disassembled from the CFRP tube. A lot of effort has gone into developing novel manufacturing and production of composites [5][6][7] and many studies for bearing strength of pin-loaded joints. For example, Sevkat et al 8 developed a new manufacturing method to improve bearing strength of pin-loaded composites, and Arman 9 studied an effect of washer type on bearing strength.…”

Section: Introductionmentioning

confidence: 99%

Development of pre-molded internal thread on composite tubes

Takano

Kitamura

Masai

et al. 2021

Composites and Advanced Materials

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Premolded internal threads on composite tubes were developed. The composite tubes with threads on both ends were made using a mandrel with a male thread. The threads can be applied to struts with adjustable end fits and composite pressure vessels with threaded caps that enable disassembly for inspection and repair. Carbon fiber-reinforced plastic (CFRP) prepregs were laid up on a mandrel, wrapped with shrink tape, and cured in an oven. The threads were built-in, without using machine cutting, and the fibers on the thread were continuous through the thread and tubes for high strength. The thread was alternately rounded, convex, and concave in shape to enable CFRP prepregs to be laid up. Two types of specimen were made and tested. The layup sequence of specimen A was [0/h/90/h/0/h(1/2)]s, and that of specimen B was [0/h/90/h/90/h/0/h/90/h/90/h/90/h/90/h/0/h/90/90/0], where “h” denotes a helical layer along the concave part of the threads. The relation between load and strain is nonlinear because of the rounded shape of the threads; however, a simple and closed form analytical model was able to predict the strength of the threads and design of the threads. The model was compared with the experimental results. In addition, an application of threads for the pressure vessel of the hybrid rocket motor is also reported. The combustion test proceeded without failure. Visual inspection after the test indicated that the threads and tubes were not damaged, and thus, they can be applied to high-pressure and high-temperature rocket motors.

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