1992 Vol. 9, No. 4
1992, 9(4): 1-6.
Abstract:
A detailed computation is performed to the vibrating and fluttering charceteeistic of composite material laminates with different off-axis angles of plies.A series of data to be used in aeroelastic tailoring purpose is obtained bated on the computation,in which the required elastic moduls are provided by fining the experiment4l data with the vribration calculated results.Finally,a comparison is demonstr aced for three kinds of laminates with different plies compared with ccrrezponrling wind tunnel test,and a satisfactory agreement is arrived.
A detailed computation is performed to the vibrating and fluttering charceteeistic of composite material laminates with different off-axis angles of plies.A series of data to be used in aeroelastic tailoring purpose is obtained bated on the computation,in which the required elastic moduls are provided by fining the experiment4l data with the vribration calculated results.Finally,a comparison is demonstr aced for three kinds of laminates with different plies compared with ccrrezponrling wind tunnel test,and a satisfactory agreement is arrived.
1992, 9(4): 7-12.
Abstract:
The static mechanical propertied of continuous glass fiber-reinforced polyethersulphone(PES),ineluding tension,compression,flexure and shear,were studied.The effects of processing condition on the properties of the composites were discussed.The fractural morphologies and failure mechanisms were analysed.
The static mechanical propertied of continuous glass fiber-reinforced polyethersulphone(PES),ineluding tension,compression,flexure and shear,were studied.The effects of processing condition on the properties of the composites were discussed.The fractural morphologies and failure mechanisms were analysed.
1992, 9(4): 13-16.
Abstract:
In the paper the elastoplaotie coistitutive relations of unidirectional fiber reinforeed composite materials were modeled numerically.The finite dlement metheod based on elastie-viscoplastic coastitutive theories was presonted,thea the micromechanics model was used to study the nonlinear stress-strain relations of compodites of which the elastie-viscoplaastic matrix is reinforced by the elastic fibers.
In the paper the elastoplaotie coistitutive relations of unidirectional fiber reinforeed composite materials were modeled numerically.The finite dlement metheod based on elastie-viscoplastic coastitutive theories was presonted,thea the micromechanics model was used to study the nonlinear stress-strain relations of compodites of which the elastie-viscoplaastic matrix is reinforced by the elastic fibers.
1992, 9(4): 17-22.
Abstract:
Response of laminated composite structures to,thermal surroundinks has been a subject of intensive studies in recent years.The thermal behaviors of laminated composite plates and shells have studied well.In this paper,the thermal deformations and stresses in stiffened composite laminates are investigated by using finite element method.Based on Mindlln hypothesis,laminated composite plate and beam theories including the effct of transverse shear deform ationane given.The fosegoingtheories arr also applicable to thick plates and bea ms.The thermal loadings considere dare transient as well as steady.The corresponding computer code are developed The application of the present model and code to practical problemshas shown that they are accurate and effective.
Response of laminated composite structures to,thermal surroundinks has been a subject of intensive studies in recent years.The thermal behaviors of laminated composite plates and shells have studied well.In this paper,the thermal deformations and stresses in stiffened composite laminates are investigated by using finite element method.Based on Mindlln hypothesis,laminated composite plate and beam theories including the effct of transverse shear deform ationane given.The fosegoingtheories arr also applicable to thick plates and bea ms.The thermal loadings considere dare transient as well as steady.The corresponding computer code are developed The application of the present model and code to practical problemshas shown that they are accurate and effective.
1992, 9(4): 23-32.
Abstract:
Based on the theory of linear-elastic fracture mechanics,the crack tip stress field of orthotropic plate is still controlled by the stress-intensity factors,therefore to study the stress-intensity factors of orthotropic plate is an important problem in studying the fracture of composite materials.At present,not a few papers calculate the stress-intensity factors by finite element theory,but few by testing technique.With composite material fracture theory,the paper derives the relation formulas between the KI、KⅡ and the v displacement with different fiberreinforced directions.In this paper,the glass fiber-reinforced orthotropic plate is worked into the pure bending beam with a unilateral cutonit,which is tested by using the sticking film moue interferometry.Through testing,the full-field displacement of the moire pattern is given,the KI and KⅡ values are further calculated from the displacement in the crack-tip.The patterns that the pure bending beam has different crack lengthes and is in different fiber-reinforced directions are given in this paper.Being exposed twice,the grating density of the moire pattern can reach 1260 line/mm.At the same time,the same specimen is calculated by using SAP-84 plate clement program on microcomputer for inspecting the testing precision.At last,the test results are compared with the calculating ones in error.
Based on the theory of linear-elastic fracture mechanics,the crack tip stress field of orthotropic plate is still controlled by the stress-intensity factors,therefore to study the stress-intensity factors of orthotropic plate is an important problem in studying the fracture of composite materials.At present,not a few papers calculate the stress-intensity factors by finite element theory,but few by testing technique.With composite material fracture theory,the paper derives the relation formulas between the KI、KⅡ and the v displacement with different fiberreinforced directions.In this paper,the glass fiber-reinforced orthotropic plate is worked into the pure bending beam with a unilateral cutonit,which is tested by using the sticking film moue interferometry.Through testing,the full-field displacement of the moire pattern is given,the KI and KⅡ values are further calculated from the displacement in the crack-tip.The patterns that the pure bending beam has different crack lengthes and is in different fiber-reinforced directions are given in this paper.Being exposed twice,the grating density of the moire pattern can reach 1260 line/mm.At the same time,the same specimen is calculated by using SAP-84 plate clement program on microcomputer for inspecting the testing precision.At last,the test results are compared with the calculating ones in error.
1992, 9(4): 33-37.
Abstract:
The constitutive relation of the ductile metal particles toughened ceramics is derived in this paper by the micromechanics analysis of theconstitutive element.The toughening contribution due to the plastic deformation of the duccile particles calculated by using the derived constitutive law of the composite.The derived theoretical relations between the material's microscopic behavior and the properties of the constituent provide basis for the further material design.
The constitutive relation of the ductile metal particles toughened ceramics is derived in this paper by the micromechanics analysis of theconstitutive element.The toughening contribution due to the plastic deformation of the duccile particles calculated by using the derived constitutive law of the composite.The derived theoretical relations between the material's microscopic behavior and the properties of the constituent provide basis for the further material design.
1992, 9(4): 39-45.
Abstract:
The mechanical property test on a metal-matrix composite (MMC) requires a high degree of statistical reliability in its experimental data due to the structural peculiarity of the material,hence a great number of specimens.This requirement,on the other hand,implies a high cost for the test considering the cmplexity in fabricating the material.It is,consequently,desirable that an economical method should be found to analyse and evaluate the mechanical properties,especially the fracture behavior,of MMC.Computer-simulation,as such an answer,was used in the present investigation to probe the fracture process of a unidirectional fibre-reinforced MMC in tension of a two-dimensional sheet with tensile axis parallel to the fibres.The ltey stage of the simulation was to establish an analytical model on which the computer program was based.The modelcombined fracture mechanics with statistics.It mainly consisted of the distribution of a fibre's ultimate strength,the statistical sequence for simulation and the stress intensification ahead of a broken fibre.Weibull's Distribution Function of probability was found to be a valid function in demonstrating the scattering character of the fibre's ultimate strength.And,Monte Carlo's Statistical Testing Method was utilized and extended to generate a stochastic sequence for distributing the strength value and forming the simulation sequence.
The mechanical property test on a metal-matrix composite (MMC) requires a high degree of statistical reliability in its experimental data due to the structural peculiarity of the material,hence a great number of specimens.This requirement,on the other hand,implies a high cost for the test considering the cmplexity in fabricating the material.It is,consequently,desirable that an economical method should be found to analyse and evaluate the mechanical properties,especially the fracture behavior,of MMC.Computer-simulation,as such an answer,was used in the present investigation to probe the fracture process of a unidirectional fibre-reinforced MMC in tension of a two-dimensional sheet with tensile axis parallel to the fibres.The ltey stage of the simulation was to establish an analytical model on which the computer program was based.The modelcombined fracture mechanics with statistics.It mainly consisted of the distribution of a fibre's ultimate strength,the statistical sequence for simulation and the stress intensification ahead of a broken fibre.Weibull's Distribution Function of probability was found to be a valid function in demonstrating the scattering character of the fibre's ultimate strength.And,Monte Carlo's Statistical Testing Method was utilized and extended to generate a stochastic sequence for distributing the strength value and forming the simulation sequence.
1992, 9(4): 47-51.
Abstract:
The development rend rescarch of tectile structural composites are reviewed in this paper.The main topics include the development and application of two-dimensional textile structural compecites,as well the research and application proepecte of multidireetional textile steutural composites.Finally,Some opinions on the tucther development of textile strucral composites are presented.
The development rend rescarch of tectile structural composites are reviewed in this paper.The main topics include the development and application of two-dimensional textile structural compecites,as well the research and application proepecte of multidireetional textile steutural composites.Finally,Some opinions on the tucther development of textile strucral composites are presented.
1992, 9(4): 53-60.
Abstract:
Thermoplastics reinforced by fibrils of thermotropic liquid crystalline polymers,so-called in-situ composites,have shown a new approach to reinforcing thermoplastics.Recent research works on in-situ composites are reviewed on the.a.spects of material ingredients,microstrucfiure and morphology,performances,processing and cost.A comparison of in-situ composites with fiber-reinforced thermoplastics has been conducted,which indicates the advantage,potential and prosperous future of this new approach.
Thermoplastics reinforced by fibrils of thermotropic liquid crystalline polymers,so-called in-situ composites,have shown a new approach to reinforcing thermoplastics.Recent research works on in-situ composites are reviewed on the.a.spects of material ingredients,microstrucfiure and morphology,performances,processing and cost.A comparison of in-situ composites with fiber-reinforced thermoplastics has been conducted,which indicates the advantage,potential and prosperous future of this new approach.
1992, 9(4): 61-67.
Abstract:
This paper deals with the manufacture of carbon fiber reinforced glass-ceramic matrix composites.Three kinds of matrlcs are used machinable phlogopite glass-seramic,icpidolite glass-ceramic and LAS glassceramic.The composite sampics are prepared by powdersintering method in laboratory.This paper improves the normal manufacture process with introducing sol-gel method in composite forming process—the key part of the powdersintering process.According to the principle of sol-gel method,the paper investigate of sol-gel formula appropriated for composite manufacture,and also makes analysis and comparison on these three kinds of glass-ceramic composites with their monolithic metrics by means of physical and chemical test method.
This paper deals with the manufacture of carbon fiber reinforced glass-ceramic matrix composites.Three kinds of matrlcs are used machinable phlogopite glass-seramic,icpidolite glass-ceramic and LAS glassceramic.The composite sampics are prepared by powdersintering method in laboratory.This paper improves the normal manufacture process with introducing sol-gel method in composite forming process—the key part of the powdersintering process.According to the principle of sol-gel method,the paper investigate of sol-gel formula appropriated for composite manufacture,and also makes analysis and comparison on these three kinds of glass-ceramic composites with their monolithic metrics by means of physical and chemical test method.
1992, 9(4): 69-76.
Abstract:
The fine structure,density,and thermal expansion coefficient of curbon fiber/aluminium/epoxy laminate (CALL) with various volume fraction carbon fiber reinforced epoxy (CFRP) have been revealed.The effect of surface treatment of reinfarced components,the ply design of CFRP/aluminium strctture,the volume fraction of CFRP,and fiber hybridism on mechanical properties of CALL were investigated.The results show that CALL is of low density,low thermal expansion,and high strength.The tensite,flexure,and shear strength of CALL are comparable with the corresponding values of aramid fiber/aluminum laminate(ARALL) and higer than the corresponding values of glass fiber/aluminium laminate (GLALL).
The fine structure,density,and thermal expansion coefficient of curbon fiber/aluminium/epoxy laminate (CALL) with various volume fraction carbon fiber reinforced epoxy (CFRP) have been revealed.The effect of surface treatment of reinfarced components,the ply design of CFRP/aluminium strctture,the volume fraction of CFRP,and fiber hybridism on mechanical properties of CALL were investigated.The results show that CALL is of low density,low thermal expansion,and high strength.The tensite,flexure,and shear strength of CALL are comparable with the corresponding values of aramid fiber/aluminum laminate(ARALL) and higer than the corresponding values of glass fiber/aluminium laminate (GLALL).
1992, 9(4): 77-82.
Abstract:
This paper introduces the major ingredients and manufacturing technique of the wood and plastic composite material,its major mehanical behaviour and physical property,and the comparison with other materials.The reinforced mechanism of composite materials is presented through observation and analysis of the microstructure forms of the composite maserials.And also brieily presents the available range of wood reinforcedplastic composite materials in this paper.
This paper introduces the major ingredients and manufacturing technique of the wood and plastic composite material,its major mehanical behaviour and physical property,and the comparison with other materials.The reinforced mechanism of composite materials is presented through observation and analysis of the microstructure forms of the composite maserials.And also brieily presents the available range of wood reinforcedplastic composite materials in this paper.
1992, 9(4): 83-86.
Abstract:
The effect of cold plasma modification on the surface of carbon fiber and aromatic polyamide fiber is very good and the tensile strength isnotably increased after treated.The influence to the tensile strength of fiber by cold plasma treatment with different pressure and different time has been discussed and a possible mechanism of the tensile strength increment is suggested in this paper.
The effect of cold plasma modification on the surface of carbon fiber and aromatic polyamide fiber is very good and the tensile strength isnotably increased after treated.The influence to the tensile strength of fiber by cold plasma treatment with different pressure and different time has been discussed and a possible mechanism of the tensile strength increment is suggested in this paper.
1992, 9(4): 87-91.
Abstract:
In this paper,the microstructures of Al/Al2O3 composites manufactured by Lanxide technique were studied in terms of analytical methods such as XRD,EPMA and SFM etc.The results indicate that Lanxide Al/Al2O3 is a Bind of ceramic matriX composite in which interconnected skeleton α-Al2O3 aets as matrix,metal Phases and voids distribute on the boundary and inside alumina's grain.Different processes make a great influence on microstructures and properties of Lanxide materials.
In this paper,the microstructures of Al/Al2O3 composites manufactured by Lanxide technique were studied in terms of analytical methods such as XRD,EPMA and SFM etc.The results indicate that Lanxide Al/Al2O3 is a Bind of ceramic matriX composite in which interconnected skeleton α-Al2O3 aets as matrix,metal Phases and voids distribute on the boundary and inside alumina's grain.Different processes make a great influence on microstructures and properties of Lanxide materials.
1992, 9(4): 93-97.
Abstract:
Non-orientation short BN fiber-reinforced HP Sialon Ceramic material was investigated by high speed blend.Ultrasonic disperse and HPsinterlng processes.Bending strengh and thermal shock resistance brhavior of the compositcs with different contcnts of BN fiber and diffcrcn HP sinteing temperatures were studied and discussed,the microstructure and crysta1 phase composition of the composites and the grain growth phenomena of the BN fiber before and after HP siatering were researched by TEM、SEM and XPD techniqres.
Non-orientation short BN fiber-reinforced HP Sialon Ceramic material was investigated by high speed blend.Ultrasonic disperse and HPsinterlng processes.Bending strengh and thermal shock resistance brhavior of the compositcs with different contcnts of BN fiber and diffcrcn HP sinteing temperatures were studied and discussed,the microstructure and crysta1 phase composition of the composites and the grain growth phenomena of the BN fiber before and after HP siatering were researched by TEM、SEM and XPD techniqres.
1992, 9(4): 99-101.
Abstract:
The uni-directioned fiber crystallize from the glass matrix in Cao-P2O5,system during spedal heat treatment.The microstructure of the crystalized glass and the mechanism of the in-situ composite reinforcemrnt have been discusaed in this paper.
The uni-directioned fiber crystallize from the glass matrix in Cao-P2O5,system during spedal heat treatment.The microstructure of the crystalized glass and the mechanism of the in-situ composite reinforcemrnt have been discusaed in this paper.
1992, 9(4): 103-106.
Abstract:
The main objective of this thesis is to investigate the rheological behavior of AG-80/DDS-MEA·BF3 epoxy rein system by means of Rheomecrics Mechanical Spectrometry.The experiments show that the temperature and lime spectrums of G'、G" tan δ and η* exhibit the relation-ship between the molecular motion and rheological behavior of the resin system during curing,providing the curing parameter for the composite system.
The main objective of this thesis is to investigate the rheological behavior of AG-80/DDS-MEA·BF3 epoxy rein system by means of Rheomecrics Mechanical Spectrometry.The experiments show that the temperature and lime spectrums of G'、G" tan δ and η* exhibit the relation-ship between the molecular motion and rheological behavior of the resin system during curing,providing the curing parameter for the composite system.
1992, 9(4): 107-110.
Abstract:
In this paper,the formability of composite laminates sheet metals was studied by bending experiments.The results indicate that the composite has its own particular forming law,the resin layer and lubricating condition will produce great effect on the composites forming.The opposite bending will occur in the process of bending,it will be dispelled when technology is improved.
In this paper,the formability of composite laminates sheet metals was studied by bending experiments.The results indicate that the composite has its own particular forming law,the resin layer and lubricating condition will produce great effect on the composites forming.The opposite bending will occur in the process of bending,it will be dispelled when technology is improved.
1992, 9(4): 111-113.
Abstract:
Aging behavior are investigated in a silicon carbide whiske reinforced LD2 aluminum alloy composite by means of microhardness measurement and TEM observation.It is found that G.P.zones occur in both of the composite and the matrix alloy after 150℃ and 170℃ aging.Aging is slightly accelerated in SiCw/LD2 composite.
Aging behavior are investigated in a silicon carbide whiske reinforced LD2 aluminum alloy composite by means of microhardness measurement and TEM observation.It is found that G.P.zones occur in both of the composite and the matrix alloy after 150℃ and 170℃ aging.Aging is slightly accelerated in SiCw/LD2 composite.
