ISSN:0272-8397    

DOI:10.1002/pc.750130602

出版商:Society of Plastics Engineers    

年代:1992

数据来源: WILEY

摘要:

AbstractIn this paper, a new composite material, AEG, which was developed in our laboratory by catalytic grafting polymerization of ethylene on asbestos fibers, was used to improve the properties of asbestos/HDPE composites. Tensile testing shows that the AEG modified asbestos/HDPE composites exhibit significantly higher tensile strength and elongation at break than the unmodified ones. Instrumented impact testing permits a detailed understanding of the modifying effect of AEG on impact properties. The records acquired during impact for the unmodified composites were truncated at the onset of initial fracture, showing a typical brittle cleavage fracture. In contrast, the records for the AEG modified composites showed an effective post‐initial fracture behavior. The load at peak, the energy required to initiate and propagate the fracture, and the deformation during impact increase dramatically for the AEG modified composites. SEM micrographs of the fractured surfaces also demonstrate the difference in the morphology of the two composite

ISSN:0272-8397    

DOI:10.1002/pc.750130603

出版商:Society of Plastics Engineers    

年代:1992

数据来源: WILEY

摘要:

AbstractThis consolidation of unidirectional APC‐2 was studied experimentally to determine the effects of processing parameters (pressure, temperature, and number of layers) on resin flow as measured by the Kozeny constant and the bulk modulus. The Kozeny constant obtained was between 0.0205 and 0.107. It was found to depend on the consolidation pressure, temperature, number of layers, and their interactions at a 99% confidence level. The value of the bulk modulus was found to be between 1.21 MPa (175 psi) and 8.58 MPa (1244 psi). It also was found to depend on the temperature, pressure, number of plies, and their interactions at a 99% confidence level. These results show the critical effects of fiber orientation on resin flow during processin

ISSN:0272-8397    

DOI:10.1002/pc.750130604

出版商:Society of Plastics Engineers    

年代:1992

数据来源: WILEY

摘要:

AbstractThe consolidation pressure and winding speed for thermoplastic filament winding were studied. Thermoplastic composite parts were manufactured from tape prepreg (APC‐2); powder‐coated, semi‐consolidated towpreg; and commingled fiber towpreg. The material used was carbon fiber (AS‐4) (60 vol%) in a PEEK matrix. The parts made were open‐ended cylinders of the three materials, 177.8‐mm ID, 228.6 mm long, 17 plies thick with a 0° lay‐up angle; and rings, 50 plies of APC‐2 thick, 6.35 mm wide (one strip wide), 177.8‐mm ID, and a lay‐up of 0°. Their quality was determined by surface finish and void percentage. The tubes made from APC‐2 appeared to have the best quality of the three prepregs. For the rings, the speed of lay‐down had a significant effect (at a 99% confidence level) on both the final width of the parts and on the percentage of voids. The pressure of the roller had a significant effect on the final widths at a 99% confidence level, but a significant effect on the percentage of voids at on

ISSN:0272-8397    

DOI:10.1002/pc.750130605

出版商:Society of Plastics Engineers    

年代:1992

数据来源: WILEY

摘要:

AbstractStudies have been conducted to investigate the aircraft fluid and chemical solvent resistance of the carbon fiber‐reinforced poly(phenylene sulfide) (PPS) and poly(ether ether ketone) (PEEK) composites. The solvents and aircraft fluids utilized in this work include hydraulic fluid, paint stripper, JP‐4 jet fuel, methyl ethyl ketone, and methylene chloride. The weight gain of the composites as a function of time is measured. Tensile and flexural strength, thermal behavior, and dynamic mechanical properties of the composites are examined. The alteration of crystallinity change of the composites is investigated by X‐ray diffraction. It is found that paint stripper degraded the mechanical properties of the composites significantly. Furthermore, crystallization enhancement of the low crystallinity composites in the presence of solvents and aircraft fluids is also obs

ISSN:0272-8397    

DOI:10.1002/pc.750130606

出版商:Society of Plastics Engineers    

年代:1992

数据来源: WILEY

摘要:

AbstractThe effect of physical aging on the penetration impact toughness and Mode I interlaminar fracture toughness of continuous carbon fiber (C.F.) reinforced poly(ether ether ketone) (PEEK) and poly(phenylene sulfide) (PPS) composites has been investigated by using an instrumented falling weight impact (IFWI) technique and a double cantilever beam (DCB) test. Composite materials studied are aged below their glass transition temperature (Tg) at various periods. Initiation force and energy of damage, failure propagation energy, impact energy and ductility index (D.I.) are reported. The Mode I critical value of strain energy release rate (GIC) of the unidirectional carbon fiber‐reinforced PEEK (APC‐2) composites is obtained. Results show that aging has a significant effect on the toughness of both composite materials. Energy absorbed during impact decreases with the increase of aging temperature and period. The PEEK/C.F. composites exhibit a higher retention of impact toughness than that of the PPS/C.F. composites after aging; however, the PPS/C.F. composites show a much higher ductility index. The Mode I fracture mechanism of the APC‐2 composite is a combination of stable and unstable failure and shows a “stick‐slip” behavior. Owing to the formation of a relative rigid structure, the fracture toughness (GIC) of APC‐2 decreased with the increase of aging temperatu

ISSN:0272-8397    

DOI:10.1002/pc.750130607

出版商:Society of Plastics Engineers    

年代:1992

数据来源: WILEY

摘要:

AbstractThe hygrothermal behavior of carbon fiber‐reinforced poly(ether ether ketone) (PEEK) and poly(phenylene sulfide) (PPS) composites subjected to moisture and temperature is investigated in this study. The properties of both composites exposed to temperature/humidity and immersed in water for extended periods are studied. Properties studied include moisture sorption, crystallinity, dynamic mechanical response, tensile strength, and flexural strength. Both the PEEK/C.F. and the PPS/C.F. composites exhibit good moisture/temperature resistance and property retention after hygrothermal exposure. The diffusivities and the equilibrium moisture absorption are measured at 60, 70, 80°C with 85% R.H. (relative humidity). A Fickian type diffusion is observed at all exposures. Crystallinity increase of the composites is found for the PPS/C.F. composites exposed to 80°C with 85% R.H. environment and is correlated with the damping properties in the dynamic mechanical study. However, the hygrothermal effect on the crystallinity and the glass transition temperature of the PEEK/C.F. composites is negligible. Mechanical properties of the PEEK/C.F. composites decrease slightly with the increase of temperature/moisture and exposure period. Mechanical property reductions of the PPS/C.F. composites decrease with the increase in exposure temperature when subjected to a similar environment; this is due to the relatively complete molecular relaxation and additional crystallization at higher temperatu

ISSN:0272-8397    

DOI:10.1002/pc.750130608

出版商:Society of Plastics Engineers    

年代:1992

数据来源: WILEY

摘要:

AbstractA technique and some preliminary results of a study of the damage state of a long fiber reinforced thermoplastic composite are presented, emphasizing the difficulty encountered when the matrix material contributes significant viscoelastic effects to the material response. The type and origin of these effects are reviewed, as is the theory that has been developed allowing for removal of the superimposed viscoelastic effects. It is demonstrated that the complicating effect of the superimposed viscoelasticity can be successfully removed, thereby providing a less confusing presentation of the data and offering the potential for greatly simplified design and analysis.

ISSN:0272-8397    

DOI:10.1002/pc.750130609

出版商:Society of Plastics Engineers    

年代:1992

数据来源: WILEY

摘要:

AbstractFiber length contributions to the reinforcement potential in composites have been decoupled from fiber orientation effects with the use of a fiber orientation model. Fiber length efficiency factors and fiber orientation factors are calculated based upon a procedure that requires measuring the composite properties in specified directions relative to a reference direction. The procedure is straightforward and relatively quick compared to the tedious task of actually measuring the fiber length distribution. An example illustrating the utility of the procedure is given and then followed by a discussion qualifying the significance of the factors and the results.

ISSN:0272-8397    

DOI:10.1002/pc.750130610

出版商:Society of Plastics Engineers    

年代:1992

数据来源: WILEY

ISSN:0272-8397    

DOI:10.1002/pc.750130601

出版商:Society of Plastics Engineers    

年代:1992

数据来源: WILEY