COMPOSITES SCIENCE AND ENGINEERING

FINITE ELEMENT MODELING AND BUCKLING STABILITY ANALYSIS OF COMPOSITE MATERIAL WIND BLADES

XUE Cai-hong, LI Jun-xiang, WANG Chao, LU Xiao-feng

2014, 0(1): 4-7.

Asbtract ( 31 )

PDF (1432KB) ( 51 )

References | Related Articles | Metrics

Based on 40 meters horizontal wind blade, the structure and loads of the wind blade were analyzed. The method of using FiberSIM, CATIA and MSC. Patran finite element software to establish the finite element model was illustrated, and the buckling stability of wind blade was calculated based on the finite element model. The result shows that the wind blade structure has a good capability of anti-buckling failure,meets the requirement of GL, the composite laminate and structure design is reasonable.

THE STUDY OF LOW-VELOCITY IMPACT PERFORMANCE OF 2.5D WOVEN COMPOSITES

YUAN Shou-ren, CAO Hai-jian, QIAN Kun

2014, 0(1): 8-12.

Asbtract ( 32 )

PDF (2034KB) ( 48 )

References | Related Articles | Metrics

In this work, PP (64tex) filaments were wrapped in the flax (33tex) surface to form PP/flax covered yarn. The covered yarns were used to weave three typical 2.5D woven fabrics(deep crossing linking, straight shallow-crossing linking and the curved one) on SU111 type automatic rapier loom. Then those woven fabrics were made into PP/ flax composites by hot pressing in the Carver hot-pressing equipment. The low-velocity impact performance of 2.5D woven composites (thickness was 1mm, fiber volume content is 48%)was texted. The results showed when the curved shallow-crossing linking composites resist to low speed impact, the biggest load(575.1N) was bigger than others, while the biggest load of deep crossing linking composites(301.74) was the smallest. When the curved shallow-crossing linking composites resisted to low speed impact, it absorbed the most energy(0.816J), while the biggest load of deep crossing linking composites(0.773) was the least.

EXPERIMENTAL STUDY ON FRP TENSION STRAIN OF CONFINED RC BRIDGE PIER WITH RECTANGULAR HOLLOW CROSS SECTION

DONG Zhen-hua, HAN Qiang, DU Xiu-li

2014, 0(1): 13-16.

Asbtract ( 42 )

PDF (1569KB) ( 47 )

References | Related Articles | Metrics

In order to determine parameters affecting FRP tension strain of confined RC bridge pier with hollow section, and propose correct formula of FRP effective tension strain, quasi-static test was carried out to ten FRP confined RC bridge piers with rectangular hollow section under unidirectional horizontal cyclic loading and constant axial compression load. Through analyzing measured FRP tension strain, it is shown that parameters affecting FRP tension strain are damage location, the type of FRP, FRP hoop ration, shear-span ration and failure mode of FRP confined bridge pier. Tested FRP tension strain is closer to the calculated results of FRP confined component with debonding failure mode, however, the difference is obvious with the calculated results under FRP rupture failure mode.

CONTACT ANGLE MEASUREMENT METHOD AND ITS ADAPTABILITY TO FIBER/RESIN SYSTEM

YANG Hao-miao, LIU Na, SUN Jing, LI Wen-juan

2014, 0(1): 17-23.

Asbtract ( 44 )

PDF (1842KB) ( 50 )

References | Related Articles | Metrics

The contact angle is an important parameter to measure the wetting properties of the surface of the material, and the contact angle measurements are important technical means to detect material characteristics, many importantly interface interactional information of solid-liquid and gas-liquid, gas-solid can be obtained by contact angle measurements, such as wetting ability, solid-liquid interfacial tension, surface roughness, chemical heterogeneity. This paper describes common methods of measurement of the contact angle, and for the characteristics of the glass fiber/resin system, and detailed analysis of the adaptability of the commonly used measuring method of the contact angle of the glass fiber/resin system, in order to explore new experimental techniques.

GLASS FIBER INFLUENCE ON FOAMING WOOD PLASTIC COMPOSITES MOLDING AND MECHANICAL PROPERTY

ZHANG Min-jie, YAN Shi-lin, YANG Ke-lun, YAN Fei

2014, 0(1): 24-27.

Asbtract ( 29 )

PDF (1658KB) ( 48 )

References | Related Articles | Metrics

Produce the enhancement of eco-friendly wood-plastic composites with chopped glass fibers mixed with wood-plastic composites. Researches show that with the increase of the content of glass fibers, the flow properties of the materials weak, the extrusion swell phenomenon is obvious and the foaming ratio decreases. Explore the degree of influence of tensile, flexural and impact properties with the addition of fiber length and content of the wood-plastic composites. The main failure mode of glass fiber reinforced wood-plastic composite materials is the glass fibers pull-out, the glass fibers breakage, the interfacial debonding, etc. By observing the interface of the tensile, bending and impact fracture, researches the main failure mode of glass fiber reinforced wood-plastic composite materials.

EFFECT OF STITCH AND OVERLAY PLACEMENT ON IN-PLANE PERMEABILITY IN LCM PROCESS

JIANG Jin-hua, CHEN Nan-liang

2014, 0(1): 28-34.

Asbtract ( 61 )

PDF (2793KB) ( 70 )

References | Related Articles | Metrics

To the study of resin in-plane flow in fabric preforms during the liquid composite molding (LCM) process, the influence of stitch mode and overlay placement styles and binder on the in-plane permeability of fabric performs were investigated by using of linear sensor device and 2D radial testing technique. The results indicate that the internal flow behavior and permeability in fabrics with different stitch and overlay placement styles and binder treatment are different significantly. If flow channels by stitch and overlay placement are along fiber direction, the permeability is higher along channel direction, which makes the principle permeabilities K₁ and K₂different significantly and flow anisotropically. If there is an angle between flow channels and fiber direction, the principle permeabilities are small difference and flow close to isotropy. The thermoplastic binder in preforms are melted in LCM process which can change the distribution of binder powders and internal pore sizes. The thermoplastic binder after melted reaction in preforms will form more discrete adhesion film groups on fiber surface and bigger channels and pores, so resin flow faster and have higher permeability than before melt reaction.

STUDY ON AN EPOXY MATRIX RESIN TOUGHENED WITH CORE-SHELL RUBBER PARTICLE

WANG De-zhi, LI Hong-feng, QU Chun-yan, MAO Yong

2014, 0(1): 35-39.

Asbtract ( 28 )

PDF (1245KB) ( 52 )

References | Related Articles | Metrics

A high temperature curing epoxy matrix resin using core-shell rubber particle as toughener and using 4,4′-diamino diphenyl sulfone as curing agent was prepared. The results showed that epoxy matrix resin obtained excellent toughness by using just 5phr CSR-1 as tougher, impact strength of which reached 29.1kJ/m² and it increased by 58.0% than before toughening, fracture toughness G_ICof which reached 306kJ/m²and it increased by 93.7% than before toughening; temperature-resistance and modulus of matrix resin toughened with core-shell rubber particle is hardly decreased, glass transition temperature of which still keep 190.4℃; curing condition determined by DSC curves and rheological curves is 125℃×1h/185℃×4h, forming temperature of hot-melt prepreg is 75~80℃.

THE TEMPERATURE EFFECT ANALYSIS OF THE COMPOSITE PRESSURE VESSELS AFTER INFLATION

ZHANG Wei, WANG Peng-fei, WANG Hao, XING Hui-xia

2014, 0(1): 40-42.

Asbtract ( 36 )

PDF (1131KB) ( 49 )

References | Related Articles | Metrics

To get the relationship between the composite pressure vessel’s pressure and temperature, and get the pressure vessel temperature stabilization time and pressure stabilization time, the tightness test of the vessel is worked in this paper. The fitting equation can be used to predict the temperature stabilization time and pressure stabilization time.

MECHANICAL PROPERTIES ANALYSIS OF SIMPLE-SUPPORTED SANDWICH COMPOSITE BEAM WITH IMBUE LAYERS

ZHAO Kai, ZHOU Ding, LIU Wei-qing, FANG Hai

2014, 0(1): 43-47.

Asbtract ( 28 )

PDF (1240KB) ( 51 )

References | Related Articles | Metrics

In this paper, the imbue layers caused by the banding layer of the composite material are considered as the functionally graded materials, and the Young’s modulus is graded through the thickness following the exponential-law and the Poisson’s ratio keeps constant. According to the governing equations of plane stress problems, the general expressions of displacements, which exactly satisfy the governing differential equations and the simply-supposed boundary conditions at two ends of the beam are deduced. Afterwards, the unknown coefficients are determined by using the upper surface and lower surface conditions of the laminated beam. Finally, the displacements and stresses in the beam are given by substituting the unknown coefficients back to the recurrent formulae. Detailed analysis compared with sandwich beams, results show that the existence of imbue layer has a certain positive role to reduce the stress of the interface layer mutation and the overall displacement of beam, and the imbue layer is thicker, the effect is more obviously.

STUDY ON CSM MODIFIED EPOXY RESIN

LIU Jing, GAO Mei-hua, SHAN Ya-li

2014, 0(1): 48-52.

Asbtract ( 30 )

PDF (1885KB) ( 54 )

References | Related Articles | Metrics

Used epoxy resin (E-44) as matrix, chlorosulfonated polyethylene (CSM) as a toughening agent, nano-TiO₂ as a filler, epoxy resin(E-44)/CSM composites were produced. The variations of tensile strength, impact strength and corrosion resistance of the composites with the modifiers respectively were studied. The experimental results show that the CSM quality TiO₂ as 5% of the E-44.6%, the composites had the best performance. The impact strength of the composites were 11.25MPa, the tensile strength of the composites were 8.775MPa, the corrosion resistance of the composites has also been obtained some improvement. The scanning electron microscopy images of the the composites impact cross-section show that modified composite fracture transition from brittle fracture to ductile fracture.

FEM SIMULATION OF FAILURE PROCESS UNDER BENDING TEST FOR CARBON FIBER REINFORCED COMPOSITES BRIDGE

ZHANG Wei, WANG Jin-hua, JING Xiao-ying

2014, 0(1): 53-58.

Asbtract ( 29 )

PDF (2210KB) ( 49 )

References | Related Articles | Metrics

It is important to know the bending failure mechanisms for designing the composite structures in engineering field. The bending damage mechanisms and failure process of carbon fiber reinforced composites bridge are reported. The bending properties were tested on fiber reinforce composites bridge by MTS-810 universal testing machine. The load-deflection curve and failure modes were obtained. Based on the real structure of composites bridge, a continuum shell element model was established. Composites bridge was incorporated with a finite element code Abaqus/Explicit to simulate the bending failure process. Load-deflection curve obtained from the finite element method and the test result has good consistency. Failure was occurred in the position of the supporting rollers. Fiber breakage, matrix cracking, delamination and plate buckling were the main failure modes of the composites bridge. The result showed that the application of FEM in predicting the mechnical properties and optimization design of composites bridge is effective.

THE ANALYSIS OF THE RADIALLY OFFSET OF THE FILAMENT-WOUND SHELL CONNECTOR THREAD STRUCTURE

LI Yang, WANG Peng-fei, XIAO Wen-gang, XIAN Bao-jun

2014, 0(1): 59-61.

Asbtract ( 30 )

PDF (1114KB) ( 50 )

References | Related Articles | Metrics

To analyze the filament-wound connector thread structure, the theoretical calculations and the finite element analysis are worked in this paper, then the thread structure radially offset is got. The result indicated that it must consider the influence of the radially elastically deformable when calculate the thread strength, which is hollow cylindrical.

ANALYSES AND EVALUATION OF THE PROBLEM CONCERNING INTERFACE CONSTITUTIVE MODEL OF CONCRETE BEAM STRENGTHENED WITH FIBER REINFORCED PLASTIC

ZENG Xian-tao, REN Zhen-hua

2014, 0(1): 62-67.

Asbtract ( 37 )

PDF (1088KB) ( 46 )

References | Related Articles | Metrics

Based on the many problems of researching about interfacial characteristics between fiber reinforced plastic and concrete, interface constitutive model of concrete beam strengthened with fiber reinforced plastic was researched. Media and the interface of concrete beam strengthened were defined, the reason difficult to obtain bond shear stress was founded, compose of interface bond-slip, rigid body sliding, the parameters and their adaptability of constitutive relationship were analysed. The problems concerning interface constitutive model of concrete beam strengthened with fiber reinforced plastic were inducted and evaluated, the experimental method researching interfacial characteristics between FRP and concrete with wide-notch concrete beam was put forward.

THE APPLICATION OF RICE BRAN IN GLASS FIBER SIZING

LV De-hui, LEI Hong, HUO Ji-chuan, GUO Jiong

2014, 0(1): 68-71.

Asbtract ( 37 )

PDF (1099KB) ( 48 )

References | Related Articles | Metrics

It is shown by experiment result that the leaching solution of rice bran by water has the potential to be applied in glass fiber sizing agent as film former. After gelatinization and filtration, the film forming ability on glass surface and the sizing ability on glass fiber of the rice bran leaching solution and the solution of imported starch film former were comparatively studied. The leaching solution with surface tension of 38.70mN/m was considered to be a good film former, which could produce glass fiber yarn with high breaking strength (i.e. 4156 cN for 68 tex).

THE ITERATION DESIGN METHOD OF AN UNMANNED AIRCRAFT COMPOSITE WING BEAM AND STRENGTH CHECK BY FINITE ELEMENT METHOD

ZHANG Cheng-lei, LIU Feng, MA Jia

2014, 0(1): 72-75.

Asbtract ( 49 )

PDF (1495KB) ( 126 )

References | Related Articles | Metrics

The inner forces of web and caps of an unmanned aircraft composite wing beam under uniformly distributed air lift is calculated based on the loading characteristics of the beam. The layer structure of the composite wing beam is designed using iterative method through Matlab programming. The design procedure is based on the classical laminate theory and maximum stress strength criterion. The finite element model of the composite wing beam is built, based on which the strength check is done using maximum stress criterion. The safety margin coefficient of each layer is given. It shows that the layer structure of composite wing beam can be properly designed by iteration method based on classical laminate theory. The iteration procedure is convergent. The least margin of safety of each layer is 0.981, which is greater than 0.5. Therefore, the design of the composite wing beam is a success which gives enough strength and light weight.

THE EFFECT OF DRYING PROCESS ON THE MIGRATION BEHAVIOR OF STARCH SIZING SOLUTION IN GLASS FIBER CAKE

DU Ting-ting , LEI Hong, WANG Hai-bin, HUO Ji-chuan

2014, 0(1): 76-80.

Asbtract ( 41 )

PDF (1548KB) ( 51 )

References | Related Articles | Metrics

The migration behavior of starch sizing solution under different drying conditions in glass fiber cake was studied. Results indicated that the organic matters diffused with the evaporation of water, and the organic content distributed in glass fibre cake presented “W” type, which was influenced by the evaporation of water and the chromatography effect of glass fiber. Simulation experiment proved that the distribution of organic matters in the fibre cake was affected by the evaporation direction of water. The distribution behavior of organic matters on glass fibre can be inducted by changing the local evaporation velocity difference of fibre cake, which can be adjusted by changing the evaporation direction of water and blowing direction during drying process.

STUDY ON PRECISE PRE-FORMING PROCESS FOR COMPLEX SURFACE TEMPLATE OF METAL COMPOSITE MOLD

ZHANG Yong-bing, SU Yan-hong

2014, 0(1): 81-84.

Asbtract ( 36 )

PDF (1473KB) ( 51 )

References | Related Articles | Metrics

Various techniques of precise pre-forming process were systematically described in this paper for template of metal composite mold with complex surface. To find a high-quality, fast and low-cost solusion for air tightness and unformity of heat transfer of mold plate, the advantages and disadvantages and key technology were introduced in great detail. Simultaneously, some corresponding examples were listed. High-quality and reliable mold tooling could be provided for producing composite parts chronically and stably.

INTRODUCTION TO RELIABILITY-BASED DESIGN OF CONCRETE STRUCTURE STRENGTHENED WITH FIBER REINFORCED POLYMER

WU Yi-bin, JIN Guo-fang, LI Min-feng

2014, 0(1): 85-89.

Asbtract ( 37 )

PDF (911KB) ( 51 )

References | Related Articles | Metrics

A critical review of the-state-of-the-art researches was addressed on the probability distribution of FRP mechanical property, reliability of concrete structure strengthened with FRP, load and reisitence factor expression and the reduction factors including resistence reduction factor and material strength reduction factor and so on. It is indicated that probability distribution was experience assumptions, reliability of strengthened structures were not comprehensive, and then the relative reisitence factor have been adapted from those in the design codes for steel reinforced concrete structures without reliability calibration. In order to make the research work more systematic and reasonable, some suggestions and furture research works based on reliability theory were put forward.

RESEARCH AND DEVELOPMENT ON DE-ICING TECHNOLOGY OF WIND TURBINE BLADE

WANG Wei, HOU Xue-jie, GUAN Xiao-ying, LI-hua

2014, 0(1): 90-93.

Asbtract ( 27 )

PDF (807KB) ( 58 )

References | Related Articles | Metrics

Wind energy is a renewable power source that produces no known significant atmospheric pollution. Wind turbines are increasingly erected for the next years. Inland sites and especially sites in mountainous areas and frontier regions, turbines will be affected by ice during standstill and operation. Ice at low temperatures will cause severe effects on the aerodynamics and thus, on the loads and the power output of the turbine. In the following sections the formation of the ice, Ice accretion profile and the problems due to icing are discussed. Beside, This paper summaries and discusses technical solutions on the systems which can be used for the cold climate conditions.

REVIEW OF OPTIMIZATION RESEARCH ON COMPOSITE MATERIAL ACOUSTICAL PERFORMANCE

ZHANG Yan-bing, REN Chun-yu, ZHU Xi

2014, 0(1): 94-98.

Asbtract ( 41 )

PDF (815KB) ( 48 )

References | Related Articles | Metrics

The composite materials are widely used in auto manufacture and ship building industry due to its excellent characteristics of vibration and noise reduction. Recently, a series of optional design work on composite materials has been carried out, and among which a lot achievements of acoustic optional design on composite material structure have been obtained. However, in current literature, few review paper regarding acoustic optimal design of composite material structure has been published. So in this paper, focused on this problem, recent research, system analysis is introduced, and problems which need to be pay attention to and develop trends are pointed out.

THE RESEARCH STATUS OF FRP SHEET ANCHORAGE TECHNIQUES

XIA Jian-fei, ZHOU Xue-hua

2014, 0(1): 99-103.

Asbtract ( 40 )

PDF (820KB) ( 53 )

References | Related Articles | Metrics

In recent years, due to the requirement of fiber reinforced polymer (FRP) reinforcing structure, more and more people began to do some in-depth research and development into the FRP sheet anchorage techniques. Existing FRP sheet anchorage techniques are roughly divided into two categories, including ordinary FRP anchorage and prestressed FRP anchorage technique. As the time of researching on such anchorage techniques is not long, some techniques are not perfect. In order to meet the demands of actual project in the future, such anchorage techniques need to be improved and optimized constantly. This article is to do some brief introductions and discussions in connection with some existing FRP anchorage techniques.

Industry information contents

2014, 0(1): 104-128.

Asbtract ( 34 )

PDF (2866KB) ( 48 )

Table of Content