COMPOSITES SCIENCE AND ENGINEERING

STACKING SEQUENCE OPTIMIZATION OF COMPOSITE LAMINATE BASED
ON ADAPTIVE GENETIC ALGORITHM AND DESIGN HEURISTICS

WANG Gong-Dong, CHEN Yan-Hai, QIU Fu-Sheng

2009, 209(2): 3-5.

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The emphases of stacking sequence of composite laminate focus on optimization method study without considering stacking sequence design heuristics.Optimization model based on design heuristics and adaptive genetic algorithm is presented and the rules of design heuristics are expressed by fuzzy IFTHEN with believe ratio.A fitness function of adaptive genetic algorithm is established by using TsaiHill rule.Rules of design heuristics are used as heuristic constraints in laminate stacking sequence optimization model.The optimization results show the superiority and practicability of the model comparing with the results calculated using adaptive genetic algorithm without rules of design heuristics.
Key words: composite material; design heuristics; stacking sequence;adaptive genetic.

ANALYSIS OF INTERFACIAL STRESS IN THE ADHESIVE LAYER OF REINFORCED
CONCRETE BEAMS STRENGTHENED WITH AFRP

TIAN Guo-Zhi, ZHAO Shu-Jing, WANGYou-Zhi, ZHANG Shen-Wei

2009, 209(2): 6-10.

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According to elastic theory and the assumption of partial combination section,considering the effect of shear deformation of RC beam and AFRP,this paper provides the analytical solution of the bonding shear stress and normal stress between the concrete surface and AFRP.In addition,with the application of boundary condition,this paper gives the interfacial shear stress and normal stress in the adhesive layer for two point loads,and plots the distribution curve of interfacial shear stress and normal stress,which demonstrates the distribution characters of stress in the adhesive layer.Finally,this paper presents methods for decreasing stress concentration at the end of AFRP,which can afford reference for the project.

NONLINEAR ANALYSIS OF FLEXURAL BEHAVIOR OF RC BEAMS STRENGTHENED
WITH NEARSURFACE MOUNTED CFRP STRIPS

WANG Xin-Guo, WANG Wen-Hua, YAO Xiao-Ping

2009, 209(2): 11-13.

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Based on experimental results of RC beams repaired by nearsurfacemounted (NSM) CFRP strips，nonlinear analysis of the whole loading behavior of strengthened beams is put forward.Calculation precedures of deflectionload and momentcurvature are presented.Analysis values of the deflection agree well with test results for some tested beams in the reference.

STUDY OF DYNAMICAL PROPERTIES OF LAMINATED
BEAMS WITH DELAMINATING DAMAGE

YUAN Guo-Qing, LI Bin, DONG Guo-Hua, ZHU Jin-Long

2009, 209(2): 14-18.

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Delaminating damage is a common damage for the laminated composites.It has been studied in this paper about the law how the dynamical properties of the laminated beams to be affected by various damages.A set of laminated composites cantilever beams， with different sizes and different position internal delaminating damages， and a set of intact beams， were made from unidirectional woven reinforced epoxy composites.The natural frequencies of those beams have been measured and calculated.A number of laws about the delaminating effect on beams’ vibration properties have been recognized.Comparing the results of experiment with numerical analysis， it is proved that the numerical analysis method applied in this paper is accurate.

BENDING ANALYSIS FOR FRP THINWALLED BOXBEAM CONSIDERING
BOTH SHEAR LAG AND HIGHORDER SHEAR DEFORMATION

FU Wu-Rong, ZHOU Shi-Gang

2009, 209(2): 19-23.

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Based on the theory of composite laminated plates, an analysis method on the FRP thinwalled box beam is established by means of the principle of minimum potential energy，and the influence of shear lag and highorder shear deformation effects is taken into account. Some numerical examples are given and the strain on the cross section and the deflection are studied. Compared with Timoshenko beam theory and the method on shear lag and firstorder shear deformation, it is demonstrated that the proposed method is effective and reliable.

THE STUDY ON CREEP BEHAVIOR OF FRP REBAR REINFORCED
ANTISEPTIC CONCRETE BEAM

YU Qi-Ming, Wu Wei-Guo, LI Jun-Xiang, YAN Shi-Lin

2009, 209(2): 24-28.

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FRP fural resin concrete which has extensive application prospect is a kind of anticorrosive new engineering material.Although its stronger in compression than cementitious concrete，its tension behavior is weak，the reinforcement of polymer concrete beams in the tension zone with pultruded profiles made of resin and glass fibers are a good compromise between strength and stiffness.In this paper，firstly the experience has performed about the bending and creep characteristic of nonFRP reinforced furan resin concrete beam and FRP reinforced furan concrete beam，the creep curves are gained of the beams under different loads by fourpoint bending tests method，analysis is carried on the viscoelasticity nature，the result shows that FRP not only enhances the furan resin concrete beams initial stiffness and strength，but also obviously reduces the creep strain of the beam.Secondly the creep model variables are determined through the least square method，the bending creep power law model are separately built of nonFRP reinforced furan resin concrete beam and FRP reinforced furan concrete beam，which is the basis of estimation of materials long term mechanics performance，and also has important project practical value to the FRP furan resin concrete structure design.

STUDY ON PROPERTIES OF COAL CLOTH/ POLYBENZOXAZINE COMPOSITE
MODIFIED WITH NANOCARBON POWDER

ZHANG Shi-Jie, ZHANG Wei, GUO Ya-Lin

2009, 209(2): 29-32.

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Interlaminar property and ablative property of coal cloth/polybenzoxazine composite modified with nanocarbon powder were studied in this paper.The results show that，when the nanocarbon powders content is 10%，the coal cloth/ polybenzoxazine composites shearing strength enhances 26% to achieve 30.3MPa，the linear ablation rate reduces 24% is 0.0154mm/s;after hightemperature at 700℃，modified composites have the high intensity retention rate.

EFFECT OF COUPLING AGENT TREATMENT ON QUASIDYNAMIC MECHANICAL
PROPERTIES OF SIO2/CE COMPOSITES

ZHU Bao-Lin, WANG Jun-Long

2009, 209(2): 33-36.

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CE was modified by nanometer SiO2.The influence of the content of nanometer SiO2 on the static mechanics performance of nanometer SiO2/CE composite material was also investigated. The influence of the material interface structure on the static mechanics performance of nanometer SiO2/CE composite material was studied by

SURFACE TREATMENT OF SILICA GLASS FIBERS IN PHOSPHATE
MATRIX COMPOSITES

ZHOU Yan, DENG Shi-Feng, HUANG Fa-Rong

2009, 209(2): 37-41.

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Three surface treatment methods were used to remove the organic surfactants on the surface of silica glass fibers.The weight loss，tensile strength and wettability of treated silica glass fibers were compared and the way of washing the silica glass fibers with 30% sulphuric acid was chosen.Al2O3 coating silica glass fibers was prepared by solgel technology.The properties of Al2O3 coating fibers and its phosphate matrix composites were discussed.The results show Al2O3 coating enhances intensity and thermal stability of the silica glass fibers.The optimal amount and heattreatment condition of Al2O3 coating are 4.6 wt% and 250℃/10min.The Al2O3 coating fibers reinforced phosphate matrix composites have well mechanical properties at room temperature and better mechanical stability after high temperature treatment.

STUDY OF MONTMORILLONITE MODIFIED CARBON CLOTH /PHENOLIC RESIN NANOCOMPOSITES

TIAN Jian-Qiu, GUO Y-Lin, WANG Bin, ZHANG Wei

2009, 209(2): 42-45.

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In this paper phenolic resin was modified with organomontmorillonite，and the exfoliation behavior of phenolic resin in the organomontmorillonite had been investigated by XRD，TEM.The montmorillonite modified carbon cloth/phenolic resin nanocomposite was prepared，and the thermal，mechanical，ablative properties were tested.It was found that the affinity between the organomontmorillonite and phenolic resin was very good.Property test results showed that the thermal，mechanical，ablative properties were improved by addition of the organomontmorillonite in the nanocomposites.

BLADES MODELING STUDY OF LARGESCALE WIND TURBINE BASED ON ANSYS

LI Cheng-Liang, WANG Ji-Hui, XUE Zhong-Min, LI Jun-Xiang

2009, 209(2): 52-55.

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It’s an important part in the process of designing blades of finite element checking and analysing,finite element modeling of blades is very cumbersome because of the complexity of the shape and structure.With finite element software ANSYS,this paper describes in detail the process of finite element modeling of largescale wind turbine blades by means of the length blade of 750kW wind turbine,some suggestions of modeling methods are put forward.In the course of modeling,the method which from down to up is adopted to build blade’s entity model,shell elements of SHELL91 and SHELL99 are combined with real constants is used to model the composite laminate structure through gridassignment and elementassignment during meshing.By setting the parameters of SHELL91,the “sandwich” characteristics can model the sandwich structure of blades.It’s the basis of finite element modeling for designing largescale wind turbine blades or analysing and checking.

RESEARCH ON SNOWMELTING CONCRETE ROAD PANELS BY
HEATING ELECTRICALLY CONTINUOUS CARBON FIBERS

CA Hao-Tian

2009, 209(2): 56-60.

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The snowmelting concrete road panels were studied by laying highstrength continuous carbon fiber with good electric properties in the concrete.To lower the cost,“the heating tapes” were laid in the concrete rather than to heat the whole road.“A heating tape” is 500mm wide,the distance of carbon fibers is 15~20mm to the surface of concrete,the spacing among carbon fibers bundles is 12mm,and the maximum design power is set in 700W/m2.The test results show that the moderate snow can be melt immediately at -13℃ and lowspeed wind when the input power is 200~300W/m2, if the concrete panel is heatedelectrically uniformly at a proper elevatedtemperature speed.

WINDING PROCESS DESIGN WITH CARBON FIBER/EPOXY ON RUBBER LINER

JIA Xiao-Long, LI Gang, XUE Zhong-Min, YANG Xiao-Ping

2009, 209(2): 61-64.

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According to the technic targets of carbon fiber winding pressure gas holder with rubber liner，the winding layer and winding tension were designed and calculated in detail on the basis of netting analysis，the winding parameters and technics were affirmed.The selected epoxy resin system with good mechanical properties had a suitable viscosity for winding. And the failure section of composite NOL ring indicated the epoxy resin could bond with T800 carbon fiber very well. The testing results for winding pressure gas holder showed that burst pressure and fatigue test met the design target of composite gas holder.

CALCULATION OF LAY DEPTH FOR COMPOSITES CABLE DUCTS

ZHOU Chu-Lin, YE Jin-Feng, YANG Hui-Fang

2009, 209(2): 65-67.

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For safety use of composites cable ducts，to save construction expense，and have a rational lay depth for the cable ducts,this paper gives the lay depth for main ducts according to the proper of composites cable ducts and angle diffusion theory of ground pressure.The caculation formula in this paper can be extended to the ducts of other gauge and other ground loads.

STUDY ON THE HIGH TEMPERATURERESISTANT BORONPHENOLIC RESIN

WANG Lei, LU Jia-Qi, ZHENG Li, ZHANG Hong-Yan

2009, 209(2): 68-71.

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The boronphenolic resin with stability properties was synthesized with industrialized method, which was useful for the extensive use of this kind of resin. The study of DSC and TGA shows that the boronphenolic resin has higher moulding temperature and better heatdurability.Boronphenolic composites have better properties than usual phenolic composites,such as bend strength,compressive strength and shear strength,as well as lower surface resistance and body resistance. After 480 hours in 250℃, the lost of bend strength is close to 50 %,which shows that the heating aging of boronphenolic composites is good.

TOUGHNESS EPOXY RESIN WITH HIGH MODULUS FOR CARBON
FIBER WET FILAMEMT WINDING

LI Mo-Yu, LIANG Qing-Biao, MENG Qiang-Yun, YANG Xiao-Ping

2009, 209(2): 72-77.

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Highperformance carbon fiber has been widely used in commercial and military fields because of its high strength， light weight and high stiffness.A series of epoxy resins were designed for carbon fiber wet filament winding.Meanwhile the mechanical property and thermal mechanical property of these resins and their carbon fiber composites were analyzed.The effect of resin matrix’s structure and property on the composite was studied based on the analysis.The results show that， for stiffness resins， the modulus of matrix is a key property to gain highperformance carbon fiber composite.With the help of the optimized resin system， the carbon fiber composite possess excellent interfacial properties and heatresistance properties.The tensile strength of T700 CF composite NOL rings is 2480MPa， that of T800 CF composite NOL rings is 2780MPa， and the glass transition temperature (Tg) is higher than 200 ℃.

PROGRESS OF STUDIES ON DURABILITY OF FIBER REINFORCED POLYMER

2009, 209(2): 78-81.

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Fiber reinforced polymer（FRP) has a widely application in civil engineering used as reinforced material.Based on the relative research results in domestic and overseas,the durability of FRP under multifarious environmental conditions,such as temperature,humidity,drywet circle,chemical corrosion and natural aging,is summarized in this paper.In addition,some urgent study aspects on durability of FRP are presented which can provide the direction for further research.

ADVANCES ON TOUGHENING MODIFICATION OF CYANATE ESTER RESIN

YOU Li-Hong, HUI Xue-Mei

2009, 209(2): 82-86.

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Cyanate ester resins (CE) have become an unique kind of highperformance thermosetting resins for being used as advanced matrix in electronic industry and aerospace.CE demonstrates many advantages including high mechanical properties，well resistantflammability characteristics，excellent electrical properties and flexibility in process.But its applications are limited for its brittle in nature and complicated manufacturing.In this paper，research on toughening modification of cyanate ester resin is summarized.Modification methods and mechanism for cyanate toughened by thermoplastics，thermosets，reactive rubber elastic body，nanoparticals are mainly described.

MARKET TRENDS OF CHINESE WIND POWER INDUSTRY AFTER FINANCIAL CRISIS

Wu Xiao-Bei, CAO Hui-Min, ZhAO Jun-Shan

2009, 209(2): 87-88.

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The subprime mortgage crisis has led to the financial crisis,caused a slowdown in the global economy，and influenced the growing wind power industry.Fortunately the financial crisis has little influence on wind power industry，especially the Chinese wind power industry， which will keep a relatively rapid growth rate in the next few years.

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