杨果, 潘勤彦, 潘皖江, 付绍云. 柔性胺改性剂对环氧树脂力学性能的影响[J]. 材料工程, 2006, 0(5): 16-20,24.
YANG Guo, PAN Qin-yan, PAN Wan-jiang, FU Shao-yun. Influence of Flexible Amine Modifier on Mechanical Properties of Epoxy Resins[J]. Journal of Materials Engineering, 2006, 0(5): 16-20,24.
龚俊杰, 王鑫伟. 薄弱环节对复合材料波纹梁吸能能力的影响[J]. 材料工程, 2006, 0(5): 28-31.
GONG Jun-jie, WANG Xin-wei. Effect of Trigger Geometry on Energy Absorption of Composite Waved-beams[J]. Journal of Materials Engineering, 2006, 0(5): 28-31.
Michael Cichon, Helen Wei Li, Alex Wong, Stan Lehmann, Raymond Wong. Henkel Technologies and Products for China Aerospace[J]. 材料工程, 2006, 0(5): 32-36.
Michael Cichon, Helen Wei Li, Alex Wong, Stan Lehmann, Raymond Wong. Henkel Technologies and Products for China Aerospace[J]. Journal of Materials Engineering, 2006, 0(5): 32-36.
Epoxy structural adhesives and composites have been in use for many years for the construction of aerospace vehicles. Henkel provides many epoxy products. Many other resin systems have been evaluated and several, such as imide, phenolic and cyanate ester, have also achieved significant use. Henkel’s newly developed “Epsilon” chemistry demonstrates unique features that benefit application in aerospace structure that use adhesives and composites.
Leonhard Maier, HU Pei, Herman Seibert. PMI Foam Cored Sandwich Components Produced by Means of Different Manufacturing Methods[J]. 材料工程, 2006, 0(5): 37-40,45.
Leonhard Maier, HU Pei, Herman Seibert. PMI Foam Cored Sandwich Components Produced by Means of Different Manufacturing Methods[J]. Journal of Materials Engineering, 2006, 0(5): 37-40,45.
The paper introduced the structural applications with PMI (Polymethacrylimide) foams in sandwich components for rotor craft, launching vehicle and civil aircraft and discuss some typically used manufacturing methods, such as e.g. in-mould pressing, autoclave curing and resin infusion. The advantages of foam-cored sandwich design versus honeycomb-cored design will be discussed, focussing on manufacturing costs.
CHENG Qun-feng, XU Ya-hong, YI Xiao-su. Toughening of BMI Based Graphite Laminates by Ex-situ Concept[J]. 材料工程, 2006, 0(5): 41-45.
CHENG Qun-feng, XU Ya-hong, YI Xiao-su. Toughening of BMI Based Graphite Laminates by Ex-situ Concept[J]. Journal of Materials Engineering, 2006, 0(5): 41-45.
High-performance bismaleimdes (BMI) matrix composites reinforced by graphite fibers were prepared and toughened with a thermoplastic component (PAEK) by using the Ex-situ concept. Experimental matrix was designed for overall toughening of the base resin, periodically interleaving thermoplastic films into each plies (Ex-situ concept) and for varying the film compositions. The highest impact damage resistance characterized by compression after impact (CAI) was obtained for the laminates toughened on the Ex-situ concept, especially, when two-component cast films of a special ration of PAEK/BMI 60:40 were interleaved though the thermoplastic concentration for the overall toughening, interleaving the pure thermoplastic films and the two-component films was comparable. There were two peaks found in the DSC trace of the laminates toughened implying a phase separation process occurred. The glass transition temperature of the laminates toughened was slightly reduced due to the low-temperature PAEK. Morphological study revealed a typical granular structure just in the interplay region as a result of spinodal decomposition and coarsening process. This was in agreement of the result of DSC investigation.
YANG Bin, XIONG Tao, XIONG Jie. Statistical Tensile Strength for High Strain Rate of Aramid and UHMWPE Fibers[J]. 材料工程, 2006, 0(5): 46-50.
YANG Bin, XIONG Tao, XIONG Jie. Statistical Tensile Strength for High Strain Rate of Aramid and UHMWPE Fibers[J]. Journal of Materials Engineering, 2006, 0(5): 46-50.
Dynamic tensile impact properties of aramid (Technora) and UHMWPE (DC851) fiber bundles were studied at two high strain rates by means of reflecting type Split Hopkinson Bar, and stress-strain curves of fiber yarns at different strain rates were obtained. Experimental results show that the initial elastic modulus, failure strength and unstable strain of aramid fiber yarns are strain rate insensitive, whereas the initial elastic modulus and unstable strain of UHMWPE fiber yarns are strain rate sensitive. A fiber-bundle statistical constitutive equation was used to describe the tensile behavior of aramid and UHMWPE fiber bundles at high strain rates. The good consistency between the simulated results and experimental data indicates that the modified double Weibull function can represent the tensile strength distribution of aramid and UHMWPE fibers and the method of extracting Weibull parameters from fiber bundles stress-strain data is valid.
LI J Y, DAI H, LI Q, ZHONG X H, CAO X Q. Improvement of Fracture Toughness Lanthanum Zirconate[J]. 材料工程, 2006, 0(5): 51-56,62.
LI J Y, DAI H, LI Q, ZHONG X H, CAO X Q. Improvement of Fracture Toughness Lanthanum Zirconate[J]. Journal of Materials Engineering, 2006, 0(5): 51-56,62.
La2Zr2O7(LZ) is a promising thermal barrier coating material for the high temperature applications. The fracture toughness and microhardness of nanocrystalline LZ (n-LZ), microcrystalline LZ (m-LZ) and LZ-5mol%8YSZ (LZ-5-8YSZ) composite (8YSZ for zirconia stabilized by 8 mol% ytrria) were studied. The n-LZ had a thermal expansion coefficient of (9.6±0.4)×10-6K-1(200～1000℃) and fracture toughness of (1.98±0.07) MPa·m1/2 which are obviously higher than those of the m-LZ ((9.1±0.4)×10-6 K-1 and (1.40±0.23) MPa·m1/2, respectively), indicating that nanofication was an efficient way to increase the toughness and thermal expansion coefficient of LZ. The composite LZ-5-8YSZ had a higher fracture toughness ((1.88±0.30) MPa·m1/2) than LZ, which was close to that of 8YSZ densified by superhigh pressure (SHP).
ZHANG Ming, AN Xue-feng, TANG Bang-ming, YI Xiao-su. Study on Cure Behavior of a Model Epoxy System by Means of TTT Diagram[J]. 材料工程, 2006, 0(5): 57-62.
ZHANG Ming, AN Xue-feng, TANG Bang-ming, YI Xiao-su. Study on Cure Behavior of a Model Epoxy System by Means of TTT Diagram[J]. Journal of Materials Engineering, 2006, 0(5): 57-62.
Curing behavior of a model epoxies system (E-54/AG-80) with DDS as hardener was studied in this paper. Round disk compression mode DMA was executed to study the gel behaviors at different temperatures to determine the relationship between gel-time (tgel) and temperature. The cure kinetics was studied by dynamic DSC analysis. Parameters were obtained for establishing a phenomenological cure reaction model. The relationship between glass transition temperature (Tg) and cure degree (α) was also analyzed by both isothermal and dynamic DSC method based on DiBenedetto equation, which gave a mathematical description of Tg as a function of both time and temperature. Consequently, characteristic temperatures such as Tg0, gelTg and Tg∞ were determined. Finally, the Time-Temperature-Transition (TTT) diagram was designed based on the data and equations.
XIONG Tao, YANG Bin, XIONG Jie, XU Xian-jian, ZHOU Kai, MAO Ming-zhong. Effect of Strain Rate on Compression Behavior of Vinyl Ester Resin Casting[J]. 材料工程, 2006, 0(5): 63-67,72.
XIONG Tao, YANG Bin, XIONG Jie, XU Xian-jian, ZHOU Kai, MAO Ming-zhong. Effect of Strain Rate on Compression Behavior of Vinyl Ester Resin Casting[J]. Journal of Materials Engineering, 2006, 0(5): 63-67,72.
Quasi-static and high strain rate compressive experiments on vinyl ester casting were carried out by means of MTS (Material Test System) and Hopkinson bar. The behaviors of the compressed unstable and fracture of the resin casting at different strain rates were investigated.The results indicate that the response behavior of the resin casting is controlled by different mechanisms at different strain rate, and some mechanical properties of vinyl ester casting are rate-dependent: the casting are destroyed in toughness model under strain rate 3.3×10-4～6.6×10-3/s, while the casting are destroyed in brittleness model under strain rate 950～5800/s. The yield stress, yield strain energy density are all increased with the increasing strain rates at quasi-static as well as at high strain rates. What is interesting is that the yield strain decreased with the strain rates increasing at quasi-static while increased at high strain rates. It is considered that the casting occurred forcing high elastic deformation at high strain rates. The damage of the specimens is mainly controlled by axial stress before unstable deformation, while mainly controlled by shear stress after unstable deformation, and then developed to fracture finally. This progress is rate-dependent: the development of the cracks inside the castings increased with the strain rate increasing.
SHEN Zhen, CHEN Pu-hui, YANG Sheng-chun. Preliminary Study on Evaluation System of Capability of Composites to Withstand Impact[J]. 材料工程, 2006, 0(5): 68-72.
SHEN Zhen, CHEN Pu-hui, YANG Sheng-chun. Preliminary Study on Evaluation System of Capability of Composites to Withstand Impact[J]. Journal of Materials Engineering, 2006, 0(5): 68-72.
This paper summarizes the authors’ experimental study on the characterization system of composite behavior to withstand impact. The content includes: (1)The dent depth is the best parameter describing the impact damage state. (2) There exists the knee point phenomenon for damage resistance behavior (i.e. the relationship between impact energy or contact force and dent depth) and damage tolerance behavior (i.e. the relationship between dent depth and compressive failure strain or stress) of composite laminates. (3) The physical meaning of the knee point phenomenon is that the failure mechanisms change of damaged composites to fiber breakage in the first front plies from matrix crack and delamination. Some suggestions on the characterization system of composite behavior to withstand impact were proposed.
