1991 Vol. 8, No. 4
1991, 8(4): 1-6.
Abstract:
In this paper,the interface of short alumina fiber reinforced aluminium alloy composite manufactured by the infiltration method was studied.T he results indicate that there are obvious interface layers between the fiber and the matrix in the composites,and the alloy elements may improve the interface wettability by suitable chemical reaction between the fiber and the matrix.The analysis of the specimen fracture also indicates that the bonding between fiber and matrix is strong enough to transmit loading from matrix to fiber so as to play a reinforcing role of the fibers.
In this paper,the interface of short alumina fiber reinforced aluminium alloy composite manufactured by the infiltration method was studied.T he results indicate that there are obvious interface layers between the fiber and the matrix in the composites,and the alloy elements may improve the interface wettability by suitable chemical reaction between the fiber and the matrix.The analysis of the specimen fracture also indicates that the bonding between fiber and matrix is strong enough to transmit loading from matrix to fiber so as to play a reinforcing role of the fibers.
1991, 8(4): 7-12.
Abstract:
Liquid metal infiltration statics and kinetics are analysised.Experiments have been made to measure its permeability.Infiltration processing and quality of C/A1 composites are discussed under four conditions.It is pointed out that wetting is not an essential condition in fabricating the composites at low pressure.High-quality composites can also be fabricated at low pressure by controlling the fibre distribution regardless of non-wetting.Finally.the non-uniform fibre-distribution infiltration technique is used to cast high-quality composites.High-tensile-strength C/A1 composites are fabricated successfully at the low pressure of 0.7MPa.
Liquid metal infiltration statics and kinetics are analysised.Experiments have been made to measure its permeability.Infiltration processing and quality of C/A1 composites are discussed under four conditions.It is pointed out that wetting is not an essential condition in fabricating the composites at low pressure.High-quality composites can also be fabricated at low pressure by controlling the fibre distribution regardless of non-wetting.Finally.the non-uniform fibre-distribution infiltration technique is used to cast high-quality composites.High-tensile-strength C/A1 composites are fabricated successfully at the low pressure of 0.7MPa.
1991, 8(4): 13-20.
Abstract:
This paper deals with the structure and properties of short carbon fiber and glass fiber hybrid reinforced Nylon 1010 composites before and after water immersion at 80℃ for 2600 hours.The fibers incoperated in composites were separated and the length of them was measured one by one and then the length distribution was calcufated.The results show that the fibers were shortened considerably during the extrusion process.There is no appreciable difference in the length distribution between carbon fiber and glass fiber.A positive(synergetic) "hybrid effect" can be observed on the mechanical behavior and friction and wear properties of these composites either before and after hot water immersion.Degradation of molecular weight of Nylon 1010 occurs during the hot water immersion and the molecular weight retention decreases with increasing the Volume fraction of glass fiber.The crystallites grew larger during the immersion,however no spherulites can be observed.The retention of mechanical properties of these composites decreases with the increase of Volume fraction of glass fiber.The interfacial adhesion between glass fiber and Nylon 1010 matrix suffers severe damage during hot water immersion and the interfacial shear strength decreases remarkably.However,the interface between carbon fiber and Nylon 1010 matrix remains well bonded after immersion.
This paper deals with the structure and properties of short carbon fiber and glass fiber hybrid reinforced Nylon 1010 composites before and after water immersion at 80℃ for 2600 hours.The fibers incoperated in composites were separated and the length of them was measured one by one and then the length distribution was calcufated.The results show that the fibers were shortened considerably during the extrusion process.There is no appreciable difference in the length distribution between carbon fiber and glass fiber.A positive(synergetic) "hybrid effect" can be observed on the mechanical behavior and friction and wear properties of these composites either before and after hot water immersion.Degradation of molecular weight of Nylon 1010 occurs during the hot water immersion and the molecular weight retention decreases with increasing the Volume fraction of glass fiber.The crystallites grew larger during the immersion,however no spherulites can be observed.The retention of mechanical properties of these composites decreases with the increase of Volume fraction of glass fiber.The interfacial adhesion between glass fiber and Nylon 1010 matrix suffers severe damage during hot water immersion and the interfacial shear strength decreases remarkably.However,the interface between carbon fiber and Nylon 1010 matrix remains well bonded after immersion.
1991, 8(4): 21-26.
Abstract:
This paper has studied the dynamic viscoelastic spectra of PP and GFRPP material at three frequences(110,35 and 11 Hz).The results of experiment indicate that thpugh the addition of glass fibers increases the [E] value of PP,the.GF in PP interfere with the completeness of crystalization.While the amount of GF in PP is moderate,the dense interface layer can be formed.Under such condition,the density of materials and [E] is the highost.The lost energies of the interfacial layer(a'-peak) stron gly rely on the value of frequency and content of fibers which can be easily observed when dense interface layer forms;the activation energy of the a'-transformation is higher than that of Tg-trnsformation.
This paper has studied the dynamic viscoelastic spectra of PP and GFRPP material at three frequences(110,35 and 11 Hz).The results of experiment indicate that thpugh the addition of glass fibers increases the [E] value of PP,the.GF in PP interfere with the completeness of crystalization.While the amount of GF in PP is moderate,the dense interface layer can be formed.Under such condition,the density of materials and [E] is the highost.The lost energies of the interfacial layer(a'-peak) stron gly rely on the value of frequency and content of fibers which can be easily observed when dense interface layer forms;the activation energy of the a'-transformation is higher than that of Tg-trnsformation.
1991, 8(4): 27-36.
Abstract:
In making an improvement on the interfacial adhesion between aramid fiber and matrix,the Motewo.Takayanagi Chemical Method was used to treat the skin layer of aramid fiber with polyfunctional opoxide.The surface structures of treated fiber were studied by IR,ele,ental analysis and XPS.The average graft degree of epoxidc on the surface of fiber was obtained for about 88mol%,which was gained from calibration curves.In this paper,the strength of interfacial adhsion was measured by Pullout Tost of monofilament.The used fiber was Aramid 1414 and the matrix was cpoxidc.Experimental rosulte showed that the interfacial adhesion strongth increasis.On the other hand,the effect of matrix on the interfacial adhesion strengh is important.The fracture surface morphologies of pulled out fiber and matrix cavity were observed bu SEM and some analysis of the damage mechanism was described.
In making an improvement on the interfacial adhesion between aramid fiber and matrix,the Motewo.Takayanagi Chemical Method was used to treat the skin layer of aramid fiber with polyfunctional opoxide.The surface structures of treated fiber were studied by IR,ele,ental analysis and XPS.The average graft degree of epoxidc on the surface of fiber was obtained for about 88mol%,which was gained from calibration curves.In this paper,the strength of interfacial adhsion was measured by Pullout Tost of monofilament.The used fiber was Aramid 1414 and the matrix was cpoxidc.Experimental rosulte showed that the interfacial adhesion strongth increasis.On the other hand,the effect of matrix on the interfacial adhesion strengh is important.The fracture surface morphologies of pulled out fiber and matrix cavity were observed bu SEM and some analysis of the damage mechanism was described.
1991, 8(4): 37-42.
Abstract:
In this paper,the bisphenol-F and a new kind of boron modified resin whose decomposition temperature was 438℃ were synthesized.Duc to the valence bond of boron the resin has saturated and chelate ring with oxygen and carbon,the moisture proof of resin was improved considerably.The high-temperature resistance of brake with this resin as matrix is enhanced.
In this paper,the bisphenol-F and a new kind of boron modified resin whose decomposition temperature was 438℃ were synthesized.Duc to the valence bond of boron the resin has saturated and chelate ring with oxygen and carbon,the moisture proof of resin was improved considerably.The high-temperature resistance of brake with this resin as matrix is enhanced.
1991, 8(4): 45-50.
Abstract:
This paper describes the cooling crystallization exothermic diagrams of melt spcimen by using differential scanning calorimetry(DSC) microscope to analyze its morphological structure.It was found in the experiment that the glass fiber(GF) has the function of heterogeneous nucleation for polypropylenc(PP) and improves the crystalline morphology of PP.High density polyethy lcnc(HDPE) has synergetic effect for hcterogeneous nucleation,and improves the brittlness of matrix resin of PP.
This paper describes the cooling crystallization exothermic diagrams of melt spcimen by using differential scanning calorimetry(DSC) microscope to analyze its morphological structure.It was found in the experiment that the glass fiber(GF) has the function of heterogeneous nucleation for polypropylenc(PP) and improves the crystalline morphology of PP.High density polyethy lcnc(HDPE) has synergetic effect for hcterogeneous nucleation,and improves the brittlness of matrix resin of PP.
1991, 8(4): 51-58.
Abstract:
Based on Agarwal's approximate strain-optic law,a new approximate strain-optic law for photoelestic composite mat; rials is proposed in this paper.The principal strain linear difference and the direction of major principal strain can be obtained from only two photoclastic measurements(isochromatic-fringe order and isoclinic angle) by means of the strain-optic law.Thus,the photoclastic analysis of composite materials becomes as easy as that of isotropic materials.Analyses of accuracy and verifications are made for the strain-optic law.The obtained result gives a smaller error than that from Agararwal's approximate strain-optic law when the principal-strain directions are near the principal directions of materials.The accuracy is significantly improved for the approximate analysis of photoelastic composite materials.Consequently,the new law provides the theoretical basis for the application of photoelastic analysis of composite materials.
Based on Agarwal's approximate strain-optic law,a new approximate strain-optic law for photoelestic composite mat; rials is proposed in this paper.The principal strain linear difference and the direction of major principal strain can be obtained from only two photoclastic measurements(isochromatic-fringe order and isoclinic angle) by means of the strain-optic law.Thus,the photoclastic analysis of composite materials becomes as easy as that of isotropic materials.Analyses of accuracy and verifications are made for the strain-optic law.The obtained result gives a smaller error than that from Agararwal's approximate strain-optic law when the principal-strain directions are near the principal directions of materials.The accuracy is significantly improved for the approximate analysis of photoelastic composite materials.Consequently,the new law provides the theoretical basis for the application of photoelastic analysis of composite materials.
1991, 8(4): 59-69.
Abstract:
In this paper the stress and deform ation in a orthotxopic hybrid laminated beam are studied.The laminated beam consists of some nonhomo-geneous sub-layers,the elasticity of which is significantly different.The shear theory is applied to each sub-layers and the perfect bonding is assumed in the interface batween adjoining sub-layers.In this paper,a set of second-order ordinary differential equations with respect to the unknown rotation angle of each sub-layer is established.Solving the differential equations,the displace ment and stress can be analytically obtained.The stress in component materials can be determined by use of the effective modulus theory and global-local method.
In this paper the stress and deform ation in a orthotxopic hybrid laminated beam are studied.The laminated beam consists of some nonhomo-geneous sub-layers,the elasticity of which is significantly different.The shear theory is applied to each sub-layers and the perfect bonding is assumed in the interface batween adjoining sub-layers.In this paper,a set of second-order ordinary differential equations with respect to the unknown rotation angle of each sub-layer is established.Solving the differential equations,the displace ment and stress can be analytically obtained.The stress in component materials can be determined by use of the effective modulus theory and global-local method.
1991, 8(4): 71-74.
Abstract:
The composite insulating tile of aluminium foil and flyash is a new type of insulating material.It is mainly made of flyash,a kind of industrial waste slag,so it has the characteristic of low cost.In addition,it is of high thermal efficiency because of the thin air layer and aluminium foil in the product.
The composite insulating tile of aluminium foil and flyash is a new type of insulating material.It is mainly made of flyash,a kind of industrial waste slag,so it has the characteristic of low cost.In addition,it is of high thermal efficiency because of the thin air layer and aluminium foil in the product.
1991, 8(4): 75-80.
Abstract:
In this paper,the acoustic emission(AE) technique is successfully applied to meassura the glass fiber fragment length distributions in Single——Fiber——Composite(SFC) test.The interfacial shear strength is determined by developing a statistical modal using a Weibull model for fiber strength.A.comparison is performed to the results of the statistical model and the model of D.Jaques and J.P.Favre,which shows that the statistical model is quite raasonable in determining the intermining the interfacial shearstrength.
In this paper,the acoustic emission(AE) technique is successfully applied to meassura the glass fiber fragment length distributions in Single——Fiber——Composite(SFC) test.The interfacial shear strength is determined by developing a statistical modal using a Weibull model for fiber strength.A.comparison is performed to the results of the statistical model and the model of D.Jaques and J.P.Favre,which shows that the statistical model is quite raasonable in determining the intermining the interfacial shearstrength.
1991, 8(4): 81-88.
Abstract:
Based on the constitutive,(quivalence theory of the multiphase solids and the microscopic mod1 of interficial damage,an analysis for the plasticity of the particulate-composites is complcacd in this paper.With the combination of theoretical formulations and the numerical calculation the macroscopic initial yield function,including the effects of the physical propcrty of the constituents,the geometric conditions and the interficial.damages,is expressed.A comparison the test values shows the reliability between the numerical results and of the theoretical analysis.
Based on the constitutive,(quivalence theory of the multiphase solids and the microscopic mod1 of interficial damage,an analysis for the plasticity of the particulate-composites is complcacd in this paper.With the combination of theoretical formulations and the numerical calculation the macroscopic initial yield function,including the effects of the physical propcrty of the constituents,the geometric conditions and the interficial.damages,is expressed.A comparison the test values shows the reliability between the numerical results and of the theoretical analysis.
1991, 8(4): 89-99.
Abstract:
The example shows thar the influence of various boundary conditions obviously exist,and the natural frequencies obtained by the analytical method proposed in this paper are lower than those of calculated results by using the approximate methods.
The example shows thar the influence of various boundary conditions obviously exist,and the natural frequencies obtained by the analytical method proposed in this paper are lower than those of calculated results by using the approximate methods.
