scholarly journals Development of pre-molded internal thread on composite tubes

2021 ◽  
Vol 30 ◽  
pp. 263498332110007
Author(s):  
Atsushi Takano ◽  
Ryuta Kitamura ◽  
Takuma Masai ◽  
Sayaka Nishino
Keyword(s):  
High Strength ◽  
Pressure Vessels ◽  
Internal Thread ◽  
Hybrid Rocket ◽  
Composite Tubes ◽  
Rocket Motors ◽  
Fiber Reinforced Plastic ◽  
Hybrid Rocket Motor ◽  
Reinforced Plastic ◽  
Concave Part

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.

IN-SITU MEASUREMENT OF PERMEABILITY BETWEEN CARBON FIBER/RESIN

2021 ◽  
Author(s):  
MASAKI ENDO ◽  
HIROSHI SAITO ◽  
ISAO KIMPARA
Keyword(s):  
Composite Material ◽  
Carbon Fiber ◽  
Carbon Fibers ◽  
Capital Investment ◽  
High Strength ◽  
Carbon Fiber Reinforced Plastic ◽  
Manufacturing Costs ◽  
Fiber Reinforced Plastic ◽  
Reinforced Plastic

Carbon fiber reinforced plastic (CFRP) is a composite material in which carbon fibers are impregnated with resin to achieve both high strength and high rigidity. CFRP is an excellent material, but it is expensive in terms of materials, manufacturing costs, and capital investment, and it takes a lot of time to complete a product. In order to solve these problems, the demand for de-autoclaving has been increasing in recent years. If molding can be performed without autoclaving, it will be possible to reduce costs and improve productivity in terms of materials and capital investment costs.

Study on Acoustic Emission Detection Technology of Fiber Reinforced Plastic Pressure Vessel

2020 ◽  
Author(s):  
Daoxiang Wei ◽  
Yuqing Yang ◽  
Jun Si ◽  
Xiang Wen
Keyword(s):  
Acoustic Emission ◽  
Pressure Vessel ◽  
Pressure Vessels ◽  
Fiber Reinforced ◽  
Fiber Reinforced Plastic ◽  
Glass Fiber Composites ◽  
Reinforced Plastics ◽  
Detection Technology ◽  
Reinforced Plastic ◽  
Emission Detection

Abstract Fiber reinforced plastics are used in pressure vessel manufacturing because of their high strength and corrosion resistance.Defects may occur in the manufacture and use of the pressure vessel. To ensure safe operation of the pressure vessel, it is necessary to conduct periodic safety assessment of the pressure vessel put into operation. It is difficult to evaluate the safety status of fiber-reinforced plastic pressure vessels by conventional nondestructive testing.Acoustic emission detection technology is a dynamic detection method, which has obvious advantages for the performance and fracture process of fiber reinforced plastic materials. ASME section V or ASTM section on acoustic emission detection of FRP pressure vessels, in which the localization of defects is mainly based on acoustic emission instruments. Due to the anisotropy of FRP material, the instrument can only give the area of the defect, and then use other non-destructive testing methods supplementary detection, so the author proposes a regional positioning method, which can locate defects more accurately. In this paper, acoustic emission detection method and lead breaking method were used to simulate the deficiency, and acoustic velocity attenuation and variation of fiber reinforced plastics were studied, and confirmative tests were carried out to obtain the positioning accuracy of the deficiency in different areas.In order to achieve the acoustic emission (AE) response behavior of stretching damage of glass fiber composites with fiber pre-broken and weak bonding, stretching tests and real-time AE monitoring of glass fiber composites were conducted.Experimental results showed that damage model such as matrix cracking and fiber fracture and bending could be occurred in the process of damage and failure. The composition and content of signal frequency of AE is also different because of difference of preset defect.

Numerical Analysis on Mechanical Properties of Beams Reinforced by CFRP Laminates

2015 ◽  
Vol 744-746 ◽  
pp. 196-200
Author(s):  
Ning Zhuang ◽  
Hao Dong Sun ◽  
Song Ge
Keyword(s):  
Large Scale ◽  
Growth Failure ◽  
High Strength ◽  
Test Results ◽  
Cfrp Laminates ◽  
Fiber Reinforced Plastic ◽  
Four Point Bending ◽  
Reinforced Plastic ◽  
Low Weight ◽  
Cfrp Sheet

Carbon Fiber Reinforced Plastic (CFRP) has been widely used in large-scale concrete infrastructure’s reinforcement and renovation because of its low weight and high strength, which promotes CFRP application in the field of civil engineering. This paper two aged beams reinforced by CFRP sheet was loaded to failure in four-point bending by laboratory experiment. Then the numerical model was built to simulate the destruction process and compared with test results. Based on the studying of this paper, the changing law of beam’s stress, ultimate bearing capacity growth, failure mode and cracking propagation was investigated during the loading process. The research has guiding significance for the design and construction of concrete structures reinforced by CFRP laminates.

Restraint of Voids Generated Inside Injection Molded Products by In-Mold Pressing Method

2018 ◽  
Vol 12 (6) ◽  
pp. 930-939 ◽  
Author(s):  
Atsushi Motegi ◽  
Tomohiro Hishida ◽  
Yasuhiko Murata ◽  
◽  
Keyword(s):  
Injection Molding ◽  
High Strength ◽  
Compression Molding ◽  
Fiber Reinforced ◽  
Pressing Method ◽  
Glass Fiber Reinforced Plastic ◽  
Fiber Reinforced Plastic ◽  
Reinforced Plastic ◽  
Injection Molded ◽  
Injection Compression Molding

In recent years, long glass fiber reinforced plastic and carbon fiber reinforced plastic have begun to be used for structural components that require high strength. As a result, thick-walled injection molded products are being manufactured. However, defects, known as voids, are generated inside the molded product and decrease the strength of the molded product, posing a significant problem at molding production sites. The partial compression method, which is a type of injection compression molding, is effective in preventing voids in thick-walled injection molding. However, there have been limited studies that comprehensively investigated the effects of the compression conditions on void prevention in thick-walled injection molding products or the shape and dimension of the molded product, or the issues in the molded product produced by applying compression. The authors have previously proposed the in-mold pressing (IMP) method, which allows the application of partial compression without the use of an injection compression molding machine and verified its validity. In this study, we proposed a compression device in which a servomotor-driven hydraulic pump actuator is used to propel a movable rod to apply compression to the melt inside the mold cavity. The IMP method using this device was applied to mold thick-walled products with thicknesses of 10 mm and greater, and the effects of compression on the generation of voids inside the molded product and the shape and dimensions of the product were investigated. The results indicate that the generation of voids can be prevented by application of this method. In addition, it was found that marginal deformations, which can pose issues, occur in the molded product when compressive stresses generated inside the molded product by compression are released after demolding.

Face Milling of Carbon Fiber Reinforced Plastic Using Poly Crystalline Diamond Tool

2014 ◽  
Vol 1017 ◽  
pp. 383-388 ◽  
Author(s):  
Jumpei Kusuyama ◽  
Akinori Yui ◽  
Takayuki Kitajima ◽  
Yosuke Itoh
Keyword(s):  
Carbon Fiber ◽  
High Strength ◽  
Face Milling ◽  
Hole Drilling ◽  
Carbon Fiber Reinforced Plastic ◽  
Fiber Reinforced ◽  
Fiber Reinforced Plastic ◽  
Reinforced Plastic ◽  
Carbon Fiber Reinforced ◽  
Poly Crystalline Diamond

Carbon Fiber Reinforced Plastic (CFRP) is a high-strength and high-elastic-modulus composite material that is hardened by impregning carbon fiber with epoxy resin. Although, many sutdies of hole drilling of CFRP have been conducted, few sutdies of face milling of CFRP have been carried out. Face milling is necessary for surfaceing of aerospace parts, which is indispensable for airplane construction. Machining of CFRP is difficult because of the extreme tool wear and delamination that occur. The authors investigated face milling of CFRP using a newly developed Poly Crystalline Diamond (PCD) tool. The resultts show, that the cutting force and surface roughness are affected by the fiber orientation of the CFRP, and that delamination can easily occur in the outer layer of face-nilled CFRP.

Application of New Design Method by High-Strength Composite Material

2014 ◽  
Vol 607 ◽  
pp. 915-919 ◽  
Author(s):  
Haruhiko Iida ◽  
Toshiaki Fujishima ◽  
Yoshifumi Ohbuchi ◽  
Hidetoshi Sakamoto
Keyword(s):  
Composite Materials ◽  
Product Design ◽  
Design Method ◽  
High Strength ◽  
New Product ◽  
Point Of View ◽  
Light Weight ◽  
Fiber Reinforced Plastic ◽  
Reinforced Plastic ◽  
Separate Product

The purpose of this study is to apply a new design method, which integrates both optimum strength and product design. Here, the collaboration of design and strength by using composite materials is administered. Many products, which are made from high strength composite materials, require new product design technology. Existing product developments tend to separate product design from product planning. The process begins from planning the shape of the product, then calculating the strength, and lastly designing the product. In our new design method, we create from an engineering point of view. By using a design method of high-strength materials, we designed a new ZIGZAG CHAIR made of carbon fiber reinforced plastic of excellent strength and light-weight.

Experimental Research on Interlaminal Shear Strength of GFRP Bridge Decks under Simulated Concrete Environment

2012 ◽  
Vol 525-526 ◽  
pp. 249-252
Author(s):  
Wei Chen Xue ◽  
Kai Fu
Keyword(s):  
Shear Strength ◽  
Bridge Deck ◽  
Bridge Decks ◽  
High Strength ◽  
Sample Surface ◽  
Fiber Reinforced ◽  
Glass Fiber Reinforced Plastic ◽  
Fiber Reinforced Plastic ◽  
Reinforced Plastic ◽  
Shear Strength Degradation

Fiber reinforced plastic (FRP) composite which has high strength, high fatigue resistance, low density, and better corrosion resistances is desirable characteristics for bridge applications, especially decks. According to the ACI 440.3R04, Glass fiber reinforced plastic (GFRP) bridge deck samples were immersed into the simulated concrete environment at 60 for 92d (corresponds to the natural environment 25 years). The results show that, with the time increased, the interlaminal shear strength of GFRP bridge decks decreased significantly. After being exposed to the simulated concrete environment for 3.65d, 18d, 36.5d and 92d, the interlaminal shear strength degradation of GFRP bridge decks were 18.69%, 25.90%, 50.93% and 53.74%, respectively. The micro-formation of the GFRP bridge deck sample surface was surveyed under scanning electron microscopy (SEM), which indicated that with the aging time increased, corrosion pits in the surface of GFRP bridge decks became more obviously and the interface between fiber and resin was severely damaged. Therefore, the degradation of FRP under the simulated concrete environment should be considered in the design of FRP bridge decks.

Numerical Investigation of a N2O/HTPB Hybrid Rocket Motor with a Dual-Vortical-Flow (DVF) Design

2017 ◽  
Vol 33 (6) ◽  
pp. 853-862 ◽  
Author(s):  
A. Lai ◽  
Y. C. Lin ◽  
S. S. Wei ◽  
T. H. Chou ◽  
J. W. Lin ◽  
...  
Keyword(s):  
Specific Impulse ◽  
Rocket Motor ◽  
Vortical Flow ◽  
Reacting Flow ◽  
Hybrid Rocket ◽  
Rocket Motors ◽  
Roll Control ◽  
Hybrid Rocket Motor ◽  
Fluid Properties ◽  
Rocket Performance

AbstractA compact hybrid rocket motor design that incorporates a dual-vortical-flow (DVF) concept is proposed. The oxidizer (nitrous oxide, N2O) is injected circumferentially into various sections of the rocket motor, which are sectored by several solid fuel “rings” (made of hydroxyl-terminated polybutadiene, HTPB) that are installed along the central axis of the motor. The proposed configuration not only increases the residence time of the oxidizer flow, it also implies an inherent “roll control” capability of the motor. Based on a DVF motor geometry with a designed thrust level of 11.6 kN, the characteristics of the turbulent reacting flow within the motor and its rocket performance were analyzed with a comprehensive numerical model that implements both real-fluid properties and finite-rate chemistry. Data indicate that the vacuum specific impulse (Isp) of the DVF motor could reach 278 s. The result from a preliminary ground test of a lab-scale DVF hybrid rocket motor (with a designed thrust level of 3,000 N) also shows promising performance. The proposed DVF concept is expected to partly resolve the issue of scalability, which remains challenging for hybrid rocket motors development.

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