• Volume 45,Issue 2,2015 Table of Contents
    Select All
    Display Type: |
    • >综述
    • Research Progress on Design of Composite CryogenicTank in Large Launch Vehicle

      2015, 45(2).

      Abstract (1120) HTML (184) PDF 1.40 M (1691) Comment (0) Favorites

      Abstract:

      Different from traditional welded aluminum鄄alloy tank, the design emphasis of composite tank is fo鄄
      cused on preventing leakage of propellant effectively, such as liquid hydrogen and oxygen, which based on the mecha鄄
      nism of micro鄄crack initiation and propagation in resin during the full service periods. Based on the structural features
      of aerospace composite tank, this paper summarized the resin matrix composite performance at low temperature, de鄄
      sign criteria of composite tank and primary structure design of tank. Finally, the application prospects of composite
      tank are also proposed.

    • Synthesis and Properties of Perfiuorocyclobutyl Aryl Ether Polymers

      2015, 45(2).

      Abstract (1139) HTML (165) PDF 975.98 K (1499) Comment (0) Favorites

      Abstract:

      In this paper, the synthesis and properties of various aryl trifiuorovinyl ether (TFV) monomers and
      their perfiuorocyclobutyl(PFCB) aryl ether polymers is discussed. Also, the potential applications include pho-tonics,
      polymer light emitting diodes (PLEDs), membranes, atomic oxygen (AO) resistant materials etc. were reviewed.

    • >计算材料学
    • Equivalent Strength Analysis of Honeycomb Sandwich PlateBased on Equivalent Theory

      2015, 45(2).

      Abstract (1209) HTML (161) PDF 2.69 M (1737) Comment (0) Favorites

      Abstract:

      In this paper an equivalent method based on sandwich plate theory is deduced and the equivalent pa鄄
      rameters of the honeycomb plate are obtained. With these equivalent parameters, the honeycomb plate FEM simula鄄
      tion model is established and honeycomb sandwich plate static analysis and random vibration analysis are completed.
      Then static and random vibration tests were made. The results indicated that the honeycomb sandwich plate theory
      based model can accurately reflect the honeycomb sandwich plate static strength characteristics and structural dynamic
      characteristics. Static strain value and the error is less than 4%, the natural vibration frequency and the error is less
      than 5%, which shows good agreement with tests results and the effectiveness of the model.

    • Finite Element Analysis of Three鄄Dimensional HollowSandwich Composites on Tensile Properties

      2015, 45(2).

      Abstract (1088) HTML (196) PDF 2.30 M (1271) Comment (0) Favorites

      Abstract:

      A new structural model was built to study tensile properties of three鄄dimensional hollow sandwich
      composites (3D composites) by using the finite element software Workbench. The distribution of stress & strain on the
      fibers, resin and the 3D composites was discussed under tensile loads of 1 mm displacement by using the model. The
      results show that the maximum value of stress occured between the overlap of X鄄shaped piles, where the 3D compos鄄
      ites damaged easily. The minimum value of stress occured on the up and down face鄄sheet, where the 3D composites
      damaged difficulty. The main loads were supported by reinforced fibers and the minor loads were supported by matrix
      resin. The main failure mode of the 3D composites are resin fracture when the 3D composites suffered tensile displace鄄
      ment loads at 1 mm.

    • Numerical and Experimental Study on the InsulationPerformance of A Rocket鄄Borne COPV

      2015, 45(2).

      Abstract (1230) HTML (155) PDF 2.41 M (1196) Comment (0) Favorites

      Abstract:

      In order to meet the demand that working temperature of the composite layer should be below 80益,
      an insulation layer is wrapped around the composite overwrapped pressure vessel (COPV) mounted in the engine com鄄
      partment of launch vehicles. Based on lumped parameter method, structural parameters and physical property data of
      a 40 L COPV, a numerical model in consideration of the radiation, conduction and convection process was estab鄄
      lished. It analyzed the insulation performance and discussed the influence of the insulation layer thickness. Moreover,
      insulation tests of the COPV wrapped by an insulation layer with the thickness of 5 mm or 10 mm were carried out.
      The numerical results agree well with the experiment measurements.

    • >新材料新工艺
    • Influence of Cu and Li Contents on Mechanical Properties andMicrostructures of Mg鄄, Ag鄄and Zn鄄Microalloyed Al-Li Alloys

      2015, 45(2).

      Abstract (1105) HTML (138) PDF 5.14 M (1604) Comment (0) Favorites

      Abstract:

      Based on 18 Al-Li alloys with various Cu (3. 24% ~ 4. 16%) and Li (0. 94% ~ 1. 44%) con鄄
      tents, the influence of Cu and Li contents on the mechanical properties and microstructures of T8 aged Al-Li alloys
      with micro鄄alloying elements of 0. 4Mg, 0. 4Ag and 0. 4Zn was investigated. The strengthening effect and microstruc鄄
      ture variation were analyzed through total non鄄solution atomic fraction of Cu and Li and their atomic ratio. The
      strengthening precipitates consisted of T1(Al2CuLi), q忆(Al2Cu) and d忆(Al3Li). With increasing the total non鄄solu鄄
      tion atomic fraction of Cu and Li and their atomic ratio, the total amounts of precipitates and the proportion of T1 pre鄄
      cipitates were increased, the alloy strength was enhanced. Lower Cu/ Li atomic ratio led to an increase in d忆precipi鄄
      tates, and therefore lowered the alloy strength.

    • Interfacial Properties and Pressure Vessel Performance ofPBO Fiber and Carbon Fiber Hybrid Composites

      2015, 45(2).

      Abstract (1123) HTML (173) PDF 2.47 M (1457) Comment (0) Favorites

      Abstract:

      The interfacial properties and pressure vessel performance of PBO fiber and T700 carbon fiber hybrid
      composites were studied in this paper. The effects of hybrid ratio on interfacial adhesion properties and water absorp鄄
      tion of hybrid composites were investigated by interlaminar shear strength (ILSS) and water absorption measurements.
      Standard 囟150 mm pressure vessels were prepared by PBO fiber and T700 carbon fiber hybrid composites. The water
      explosion and axial bearing tests of 椎150 mm pressure vessels were conducted. The results indicate that the ILSS of
      hybrid composites went up with hybrid ratio increasing, the interfacial adhesion properties of hybrid composites saw
      little improvement as T700 carbon fiber content was lower. The water absorption values of hybrid composites were be鄄
      tween PBO and T700 fiber reinforced composites, which matches the mixture law nearly, and the number of interface
      had remarkable effect on water absorption of hybrid composites. The PV/ W of 囟150 mm pressure vessels prepared by
      hybrid composites decreased as hybrid ratio increasing. The axial bearing property of PBO fiber reinforced composites
      was improved by 31% with hybrid technology.

    • Dispersion of Carbon Nanotubes in Epoxy Resin

      2015, 45(2).

      Abstract (1080) HTML (137) PDF 2.34 M (1301) Comment (0) Favorites

      Abstract:

      The dispersion of carbon nanotubes in epoxy resin fabricated in different technological conditions was
      macroscopical characterized by stewing oberservation, viscosity and fineness respectively. The results reveal that as
      the dispersion of carbon nanotubes is good, the viscosity of epoxy is big, the fineness is low, and the conserving time
      is long. There are three means could all characterize the dispersion uniformity of carbon nanotubes, viscosity and fine鄄
      ness could characterize the dispersion of carbon nanotubes quickly, but the specific evaluation criterion should be
      found before. In this paper, the dispersions of carbon nanotubes were characterized quickly by establishing the corre鄄
      sponding relation of scraper fineness and the dispersion. This method is quick, direct, accurate and easily operated,
      compared to conventional micro-characterization technique.

    • Interlaminar Toughness Optimizing for T800/5228A Composite

      2015, 45(2).

      Abstract (1122) HTML (189) PDF 4.76 M (1212) Comment (0) Favorites

      Abstract:

      T800/5228A composite is toughned Interlaminately with PAEK, and FESEM. GIC and GIIC is tested
      and analysized comparatively. FESEM show that PAEK/5228A bi鄄continue microstructure form in T800/5228E inter鄄
      laminate, of which composite is named for the PAEK toughned T800/5228A. Data of GIC and GIIC increase 68. 01%
      and 30. 97% respectively, due to “hammer effect冶. Crack in “z direction冶and “plastic distortion冶probably in subse鄄
      quent FESEM research, and deformation interspace is restricted for GIC characterization responsible for the low鄄grade
      toughness improvment comparative to GIIC characterization.

    • Catalyzed Polymerization of the Cyclic Silazane and ItsThermal Decomposition to Si3 N4

      2015, 45(2).

      Abstract (1111) HTML (145) PDF 1019.41 K (1378) Comment (0) Favorites

      Abstract:

      A polysilazane PHSZ with high molecular weight was prepared via the polymerization of cyclic si鄄
      lazane MHSZ in the presence of tetrabutylammonium fluoride as catalyst. MHSZ was synthesized by the ammonolysis
      of methylhydrodichlorosilane. Combined with apparatus of IR, NMR, GPC and TGA, the effect of polymerization time
      on the composition, structure, molecular weight and ceramic yield of PHSZ was studied. The structure and composi鄄
      tion of the pyrolyzed products in the atmosphere of ammonia combined with nitrogen were investigated. It is suggested
      that the molecular weight of the polymer PHSZ improved with the extension of the reaction time and TGA decreased;
      PHSZ converts into Si3N4 ceramic matrix composites with a carbon content of 0. 5wt%, the product of pyrolysis at 1
      600益is completely crystallized, the crystal phase is mainly 琢-Si3N4.

    • Curing Properties of Tetraphenol Ethane Epoxy Resin

      2015, 45(2).

      Abstract (1637) HTML (234) PDF 906.05 K (1502) Comment (0) Favorites

      Abstract:

      This paper focus on studying the effects of two different curing agents (tetrahydromeythyl-1,3-iso鄄
      benzofurandione MeTHPA, and 4,4-diaminodiphenyl sulfone DDS) on curing reaction and curing properties of 1,1,2,
      2-tetrakis(4-hydroxyphenyl)ethane tetraglycidyl ether(TGE). The curing behavior of the TGE was characterized by
      scanning calorimetry analysis (DSC). The results demonstrated that curing reaction activating energy of two epoxy res鄄
      in/ hardener systems were 65.8 kJ/ mol and 68.4 kJ/ mol, respectively. The curing resin thermal properties and mechan鄄
      ical properties were investigated by dynamic mechanical analysis (DMA), thermal gravity analysis (TGA) and universal
      testing machine, respecticaly. The glass transition temperature(Tg) of MeTHPA system is 188益. Tensile and flexural
      strength is 33 MPa and 48 MPa. The Tg of DDS system is 203益. Tensile and flexural strength is 61 MPa and 93 MPa.

    • Effect of Densification Methods on Properties of Needled Felt WithNon鄄Woven Cloth Reinforced C/ C Composites

      2015, 45(2).

      Abstract (1249) HTML (199) PDF 1.57 M (1249) Comment (0) Favorites

      Abstract:

      In this paper, two processes for preparing needled felt with non鄄woven cloth reinforced C/ C compos鄄
      ites are compared. Needled preforms are treated firstly with a CVI pre鄄densified process, and then the preforms are
      densified by pitch impregnation/ carbonization. The results show that the tensile strength in axial direction is increased
      by 234%, the interlaminar shear strength is increased by 126%. In addition , the thermal diffusivity is obviously in鄄
      creased, while the axial coefficient of thermal expansion( CTE) is decreased. It is concluded that the material has
      good comprehensive properties.

    • Preparation and Mechanical Properties of New 3D Fabric Sandwich Composites

      2015, 45(2).

      Abstract (1256) HTML (185) PDF 1.84 M (1776) Comment (0) Favorites

      Abstract:

      Glass fibers were used as raw material, and the special 3D weaving process was used to weave the new
      3D sandwich fabric whose warp cross section was a rectangle. The resin matrix was consisted of epoxy resin E-51 and cu鄄
      ring agent 9055. The 3D sandwich fabric was made into 3D fabric sandwich composite through the hand lay鄄up process. The
      mechanical properties of 3D fabric sandwich composites with core height of 10 mm, 20 mm and 30 mm were studied. And
      the effect of core height on the compression properties and flexure properties of the composites were mainly analyzed. The
      results show that the compressive strength and compressive elasticity modulus of the composites decrease with the increase
      of core height. The flexural strength of the composites increase with the increase of core height, while the flexural elasticity
      modulus decrease. And the flexural strength in weft direction is better than that in warp one.

    • Effect of Resin Content on Performances of Aramid Fiber Reinforced Composites

      2015, 45(2).

      Abstract (1113) HTML (169) PDF 5.43 M (1229) Comment (0) Favorites

      Abstract:

      The F-8H3/602 aramid fiber reinforced composites laminates with different content of epoxy resin
      were prepared. The effect of resin content on impact toughness, interlaminar shear strength and flexural properties
      were studied. The morphologies of damaged samples were observed by microscope and scanning electronic microscopy
      (SEM). The results indicated that impact toughness, interlaminar shear strength and flexural properties were close re鄄
      lated to the resin content of aramid fiber reinforced composites. For F-8H3/602 aramid fiber reinforced composites
      with 46. 02wt% resin content, the impact toughness, interlaminar shear strength and flexural strength were 22 J/ cm2,
      49. 1 MPa and 506 MPa respectively. At certain weight content of resin, the mechanical properties of aramid fiber re鄄
      inforced composites in 0毅direction were much better than in 90毅direction. The interface between fiber and matrix of F
      -8H3/602 composites was weak according to SEM images of samples.

    • Mechanical Property Degradation Mechanism ofPolyimide Film by Proton Radiation

      2015, 45(2).

      Abstract (1236) HTML (193) PDF 2.80 M (1163) Comment (0) Favorites

      Abstract:

      The mechanical property and mechanism of polyimide film in proton radiation was studied by 椎800
      combined space radiation test facility of Beijing Institute of Space Environment Engineering (BISSE) and X-ray Pho鄄
      toelectron Spectroscopy(XPS). The following results can be obtained: the rupture elongation and tensile strength of
      polyimide exponential decreases with the increase of proton radiation fluence, and its elastic modular keep steady.
      The polyimide film has good thermal stability in proton radiation environment, but its transmittance in ultraviolet and
      visible range decrease and has red shift effect. The breakage and cross linkage of molecular bond is the major cause of
      decrease of polyimide爷s mechanical property in proton radiation environment.

    • Process Optimization and Performance forElectroless Plating of Ni-Co-P

      2015, 45(2).

      Abstract (1361) HTML (177) PDF 1.13 M (1212) Comment (0) Favorites

      Abstract:

      A3 steel is used as the base material steel in electroless Plating of Ni-Co-P, The best formula and
      process conditions are acquired by using the orthogonal experiment methods. The morphology,corrosion resistance, hard鄄
      ness,thickness and binding force of coating are tested and analysed. The optimum formula and the technological conditions
      are required as follows:35.0 g/ L NiSO4·6H2O, CoSO4·7H2O 4.0 g/ L, NaH2PO2·H2O 30.0 g/ L, Na3C6H5O7·2H2O
      60.0 g/ L, H3BO3 35.0 g/ L C3H6O3 12.0 mL/ L, C18H29NaO3S 0.05 g/ L, CN2H4S 2 mg/ L, pH value of 7.0, the tempera鄄
      ture of 90益, and the plating time of 2 h. Under this condition, the deposition rate is faster, up to 89.83 g/ (m2·h), the
      coating has stronger corrosion resistance, copper sulfate drip experiment time is 285 s; the surface of the coating is smooth
      and uniform;the distribution of porosity is smaller;there is better binding force with substrate.

    • Contrast of 62Sn36Pb2Ag Solder and 63Sn37Pb SolderUsed in Silicon Battery

      2015, 45(2).

      Abstract (1146) HTML (178) PDF 1.49 M (1398) Comment (0) Favorites

      Abstract:

      The performance and the microstructure analysis were carried out on 62Sn36Pb2Ag solder and
      63Sn37Pb solder used in silicon battery of analog sun sensor by mechanical test and accelerated thermal cycle test.
      Results show that the granulated Ag3Sn plays the role of dislocation pining effectively in 62Sn36Pb2Ag solder because
      of the addition of Ag element. In strengthening the joints, the granulated Ag3 Sn also improves the resistance to the
      thermal mismatch and the creep of the solder. After experiencing mechanical test and the temperature cycle test from
      -105 to +105益, the crack growth rate of 62Sn36Pb2Ag joint is much less than the 63Sn37Pb joint. Under the cer鄄
      tain test condition in the article, the resistance to the thermal mismatch and the creep of 62Sn36Pb2Ag is better than
      63Sn37Pb solder.

    • Forming Technology of Special鄄Shaped Component

      2015, 45(2).

      Abstract (1206) HTML (177) PDF 3.82 M (1748) Comment (0) Favorites

      Abstract:

      This paper takes H鄄bending waveguide as a typical component to study, the forming of special鄄shaped compo鄄
      nent. 138益of low melting point alloy used in the process of research as the core mould material to mold design and core mould
      molding parameter are found.The lamination process is simulated with DELMIA, which is benefit for saving the pre鄄assembly.
      The results show that using low melting point alloy as core has a high stripping efficiency comparing with chemical dissolved
      core, which make the batch production possible and provide the technical support for special鄄shaped components.

    • Experimental Study on M40/4211 Composite Laminates Milling

      2015, 45(2).

      Abstract (1014) HTML (159) PDF 1.98 M (1148) Comment (0) Favorites

      Abstract:

      This paper analyzes the performance characteristics of CFRP and its impact on the cutting perform鄄
      ance. The selection principles of milling tool material and geometry are proposed, several milling tools which are suit鄄
      able for CFRP are introduced. Through a series of M40 defects testing and milling testing, influencing factors and laws
      of M40 processing quality are summarized. The best processing parameters for each kind of milling tools machining
      M40 are obtained. As a result, the condition of higher cutting speed and proper feed rate can improve M40 processing
      quality and efficiency.

    • >测试分析
    • Analysis on Defects in TA15 Titanium Alloy Bar

      2015, 45(2).

      Abstract (1421) HTML (211) PDF 2.39 M (1249) Comment (0) Favorites

      Abstract:

      Bright ghost defect were found on products which made of TA15 titanium alloy bar when macroscopic
      test. The microstructure is observed, by which the abnormal area for TA15 is principally determined . The chemical
      compositions of that area is charactered by SEM,and the microhardness is tested by microhardness tester. The results
      show that the titanium content in the segregation is higher than that in the normal area, the aluminum content in the
      segregation is lower than that in the normal area, and the Vickers hardness in the segregation area is lower than that in
      the normal area, that is so called non鄄brittle segregation metallurgical defect . For the material of TA15 with segrega鄄
      tion structure, when the properties is according with the standard, the bar can be delivered as long as cut鄄off the seg鄄
      ment with segregation.

    • Effects of Gravity in Horizontal Loaded Static Test for Wind Turbine Blade

      2015, 45(2).

      Abstract (1035) HTML (156) PDF 907.80 K (1292) Comment (0) Favorites

      Abstract:

      Both of the attaching loads and the coupling displacements of gravity in horizontal loaded static test for
      wind turbine blade is analyzed in this paper. The numerical results show that the superimposition of gravity has great
      effect on the measured values, which lead to the risk of overloading the target load in some section. In order to reduce
      the overloading peak value of the equivalent load ,it is suggested that the comprehensive application of optimizing in鄄
      stallation angle of the blade and loading direction should be used based on FEM.

Current Issue


Volume , No.

Table of Contents

Archive

Volume

Issue

Most Read

Most Cited

Most Downloaded