1986 Vol. 3, No. 2
1986, 3(2): 1-Ⅰ.
Abstract:
The preparing method of continuous prepreg tapes of carbon fiber with impregnating machine are investigated.The factors effecting on the resin content,appearence,volatile content of prepreg tapes are discussed.The optimum processing parameters fro preparing prepreg tapes are given.The coutinuous unidirectional prepreg tapes,having a maximum width of 300 mm and a legth of 200m,can be manufatured with the machine.
The preparing method of continuous prepreg tapes of carbon fiber with impregnating machine are investigated.The factors effecting on the resin content,appearence,volatile content of prepreg tapes are discussed.The optimum processing parameters fro preparing prepreg tapes are given.The coutinuous unidirectional prepreg tapes,having a maximum width of 300 mm and a legth of 200m,can be manufatured with the machine.
1986, 3(2): 10-Ⅱ.
Abstract:
The hybrid carbon-fiber/glass-fiber reinforced nylon 1010 is prepared by extrusion and injection moulding.The fibers are oriented along the direction of the flowing of injected or extrude material.The fibex average length and the dispersity of length distribution are considerably altered by injection as compaced with extruded materials.Obvious positive hybrid effects are found for either mechanical properties or triboloby behaviors.Excellent interfacial bonding between feber and manix is visualized by SEM micrography.
The hybrid carbon-fiber/glass-fiber reinforced nylon 1010 is prepared by extrusion and injection moulding.The fibers are oriented along the direction of the flowing of injected or extrude material.The fibex average length and the dispersity of length distribution are considerably altered by injection as compaced with extruded materials.Obvious positive hybrid effects are found for either mechanical properties or triboloby behaviors.Excellent interfacial bonding between feber and manix is visualized by SEM micrography.
1986, 3(2): 20-Ⅱ.
Abstract:
This paper studied the mechanical properties anal fracture morphologies of glass,carbon and carbon/glass hybrid filer reinforced PSF/WSP composites.A formula was given which can estimate or design the mechanical propertics of the hybrid composites from the properties of the single composite.Eapcrimental results showed that not only the new blend PSF/ESF can be reinforced but also a more excellent and cleaper composite may be fabricated by hynrid fibers.
This paper studied the mechanical properties anal fracture morphologies of glass,carbon and carbon/glass hybrid filer reinforced PSF/WSP composites.A formula was given which can estimate or design the mechanical propertics of the hybrid composites from the properties of the single composite.Eapcrimental results showed that not only the new blend PSF/ESF can be reinforced but also a more excellent and cleaper composite may be fabricated by hynrid fibers.
1986, 3(2): 27-Ⅲ.
Abstract:
The excess enthalpy relaxation(EER) process and changes of physical and mechanical properties in a crossly linked unsaturatel polyetes annsaled at temperatures below Tg have been studied.The results suggest that not only the amount of EER as determined from the endothermic peak in Tg interval but also the density,Tg and the real part of Yong's,modulus increase with annealing time,while the imaginary patr of the modulus and the internal fricton decrease.The activation energy of EER proeess determined from the rate of EER as a function of annealing temperature is about 7Keal/mole.The molecular mechanism of EER proeess is discussed.
The excess enthalpy relaxation(EER) process and changes of physical and mechanical properties in a crossly linked unsaturatel polyetes annsaled at temperatures below Tg have been studied.The results suggest that not only the amount of EER as determined from the endothermic peak in Tg interval but also the density,Tg and the real part of Yong's,modulus increase with annealing time,while the imaginary patr of the modulus and the internal fricton decrease.The activation energy of EER proeess determined from the rate of EER as a function of annealing temperature is about 7Keal/mole.The molecular mechanism of EER proeess is discussed.
1986, 3(2): 33-Ⅲ.
Abstract:
The patterns of the amplitude distributions of the acoustic emission for various kinds of GFRP are determined to imitate some fundamental failure moles such as matrix crazing,fibex-matrix interface failure,delamination and fiber breakage.Two kinds of laminates are made of glass-weave/resin and glass-fiber/resin prepregtapes.Various kinds of stacking sequences,including 0°,±45°,0°/90°,are selected.The amplitude distributions of the acoustic emission are monitored at various loading stage.The amplitude distributions of the resin specimens with different glass fiber bunches are also investigated.
The patterns of the amplitude distributions of the acoustic emission for various kinds of GFRP are determined to imitate some fundamental failure moles such as matrix crazing,fibex-matrix interface failure,delamination and fiber breakage.Two kinds of laminates are made of glass-weave/resin and glass-fiber/resin prepregtapes.Various kinds of stacking sequences,including 0°,±45°,0°/90°,are selected.The amplitude distributions of the acoustic emission are monitored at various loading stage.The amplitude distributions of the resin specimens with different glass fiber bunches are also investigated.
1986, 3(2): 39-Ⅳ.
Abstract:
Optimality Criteria Method (OCM) has been successfully used in the optimum design of fiber reinforced composite structures with stress and displacement constraints.The default of OCM for this kind problem is that its efficienty is not very high and the interation history is rather long.In this paper,reciprocal variables have been used and the original problem has been replaced by a dual problem in quadratie form and by SQPM,and then the dual problem of mathematical programming has resulted in a very efficient method of composite structural ooptimization.The results of comparison of the two methods in one example are presented.The project is suported by the Science Fund of the Chinese Academy of Science.
Optimality Criteria Method (OCM) has been successfully used in the optimum design of fiber reinforced composite structures with stress and displacement constraints.The default of OCM for this kind problem is that its efficienty is not very high and the interation history is rather long.In this paper,reciprocal variables have been used and the original problem has been replaced by a dual problem in quadratie form and by SQPM,and then the dual problem of mathematical programming has resulted in a very efficient method of composite structural ooptimization.The results of comparison of the two methods in one example are presented.The project is suported by the Science Fund of the Chinese Academy of Science.
1986, 3(2): 48-Ⅴ.
Abstract:
The stress response in composite laminates can be effected by changing the properties of fibers and matrices.According to this assumption,a study on the effect of matrix properties on the distributions of interlaminar stresse is presented.Tsai's method is used to predict the lamina properties from fiber and amtrix properties.Three kinds of matrices are chosen for the investigation and their moduli are significanly different from on another.
The stress response in composite laminates can be effected by changing the properties of fibers and matrices.According to this assumption,a study on the effect of matrix properties on the distributions of interlaminar stresse is presented.Tsai's method is used to predict the lamina properties from fiber and amtrix properties.Three kinds of matrices are chosen for the investigation and their moduli are significanly different from on another.
1986, 3(2): 54-Ⅴ.
Abstract:
A eriterion of tesor mullinomial of strength is thcoreliual]y analysed and the strength envelopes of laminates with different F12 are given.The effect of F12 on tire envelopes is shown and a method to determine interaction coefficient F12 is proposed.The criterion is verified with two experiments.The results show that Tsai-Wu criterion of tensor multinomial is in excellent agreement with theoretical values in the tension-shear space.And the values from the experiments are in agreement with the tension-shear space.And the values from the experiments are in quadrant 1 and 4.
A eriterion of tesor mullinomial of strength is thcoreliual]y analysed and the strength envelopes of laminates with different F12 are given.The effect of F12 on tire envelopes is shown and a method to determine interaction coefficient F12 is proposed.The criterion is verified with two experiments.The results show that Tsai-Wu criterion of tensor multinomial is in excellent agreement with theoretical values in the tension-shear space.And the values from the experiments are in agreement with the tension-shear space.And the values from the experiments are in quadrant 1 and 4.
1986, 3(2): 64-Ⅵ.
Abstract:
The paper deals with the vibration analysis of thick composite laminates.For the parpose of good accracy and effieieny,the paper introduces the elastic theory of isptropic material thick plate and presents a new refined theory of laminated plates and gives some theoretieal solutions under certain pacticular boundary conditions,For general cases,the paper extends the finite elemet method to the dynamic analysis of the composite laminated plates,and develops a new element which accoants for the shear deformation,in-plane displacements and roatory inertia effects.
The paper deals with the vibration analysis of thick composite laminates.For the parpose of good accracy and effieieny,the paper introduces the elastic theory of isptropic material thick plate and presents a new refined theory of laminated plates and gives some theoretieal solutions under certain pacticular boundary conditions,For general cases,the paper extends the finite elemet method to the dynamic analysis of the composite laminated plates,and develops a new element which accoants for the shear deformation,in-plane displacements and roatory inertia effects.
1986, 3(2): 74-Ⅶ.
Abstract:
A weakest-ehain statistical model is proposed to prediet the strength of unidirectional fiber reinforced compsite materical using the chain-bandle strenth and is testified by the tension experimients of unidirectional laminates.According to this statistical strength model,the strength of unidirectional fiber renfored composite materials is in accordance withe Weibull distribution.
A weakest-ehain statistical model is proposed to prediet the strength of unidirectional fiber reinforced compsite materical using the chain-bandle strenth and is testified by the tension experimients of unidirectional laminates.According to this statistical strength model,the strength of unidirectional fiber renfored composite materials is in accordance withe Weibull distribution.
1986, 3(2): 82-Ⅶ.
Abstract:
This paper reviewed a lot of evisting formia for predicting the elastic constauts of unidirectional composites.The resalts prelicted from these formulas were compared with experimental data for unilintional Glass/Eppxy and Graphite/Epoxy composites.Some of the formulas were recommanied for calcuating the elastie constants of unidirectional composites.
This paper reviewed a lot of evisting formia for predicting the elastic constauts of unidirectional composites.The resalts prelicted from these formulas were compared with experimental data for unilintional Glass/Eppxy and Graphite/Epoxy composites.Some of the formulas were recommanied for calcuating the elastie constants of unidirectional composites.
1986, 3(2): 90-Ⅷ.
Abstract:
The hybrid stress model for fiber reinforced copposite laminates is derived by the principle of modified complementary energy.The effect of transverse shear deformation is considered and angle of rotation of surface normal for each layer is different.
The hybrid stress model for fiber reinforced copposite laminates is derived by the principle of modified complementary energy.The effect of transverse shear deformation is considered and angle of rotation of surface normal for each layer is different.
1986, 3(2): 95-Ⅷ.
Abstract:
In older to study the fatigue life distribution of unidirectional graphite/epoxy composite,50 specimeus were tested at same stress level.(αmax=48 kgf/mm2).X2 test and check with the graph on the normal probability paper are used.If the logarithmic fatigue life of htese 50 specimens as a sample is taken from same population of Gaussian distribution.
In older to study the fatigue life distribution of unidirectional graphite/epoxy composite,50 specimeus were tested at same stress level.(αmax=48 kgf/mm2).X2 test and check with the graph on the normal probability paper are used.If the logarithmic fatigue life of htese 50 specimens as a sample is taken from same population of Gaussian distribution.
