Papers by Keyword: Bending Modulus

Abstract: The bending behavior of single-walled cubic zirconia nanotubes (CZNTs) is studied in this paper based on a three-dimensional finite element analysis with molecular bonds modeled as structural beam elements and positioned at the joints of beams as substitute of atoms. In order to simulate the bending effect of CZNTs, the free-end is exposed to varying transverse displacements and the maximum force along the cross section at the fixed end is recorded to estimate the bending elastic modulus. The result obtained indicates that the bending elastic modulus of CZNTs depends on chirality and magnitude of applied transverse displacement. The simulated bending modulus of CZNTs fluctuates with the optimum value obtained from the zigzag configuration when 0.5 – 1.0 nm transverse displacement was applied. The results follows similar trend with what was obtained in other studies for carbon nanotubes but at comparatively lesser magnitude.

Abstract: Al honeycomb core sandwich composite panels have different core and plate materials. The core is the Al honeycomb core, and the thin plate is GFRP sheets with fibers laminated in the 0°/90° symmetric structure. The Al honeycomb core sandwich composite panel is used for structures, which involve relatively high bending load. Before designing the structures, their stability is evaluated via the finite element analysis. In this study, an analysis method that is closest to the reality was proposed for designing the structures with Al honeycomb core sandwich composite panels. For that purpose, the modulus was reviewed. In the finite element analysis, the tensile modulus is generally used. In the results of this study, however, the tensile modulus led to significant deviations from the test results, whereas the bending modulus led to a closer value to the test results.

Abstract: In the paper, the mathematic model of bending modulus was established by means of classic mechanical theory, Layer number and gradient factor K were used to control component distribution of gradient IPN. Polyurethane(PU)/Epoxy(EP) gradient IPN with different component distribution were prepared , The effect of component distribution variation on bending modulus of gradient IPN was studied. The results indicated that bending modulus of gradient IPN decreased with increase of layer number n and gradient factor K, the gradient factor K had greater effect on bending moulus of gradient IPN than layer number. The results were explained according to bending rigid coefficient distribution of singel layer calculated by the mathematic model.

Abstract: In this paper, a kind of composite laminates whose reinforcement is four-layer biaxial weft knitted (FBWK)fabric made of carbon fiber as inserted yarns has been made. The composite laminates have been impregnated with epoxy resin via resin transfer molding (RTM) technique. The samples of the experiments have been made from the composite laminates. The bending properties of the FBWK fabric reinforced composite materials with different fiber volume fraction have been investigated. The results show that the bending strength of this kind of composites increases with the fiber volume fraction increasing. The bending strength of FBWK reinforced composites with fiber volume fraction of 52% can reach 695.86 MPa. And the relationship between bending load and deflection is obviously linear.

Abstract: This paper records the laboratory experiments on mechanical properties of bamboo plywood.According to related test codes, The mechanical properties such as bending modulus, bending capacities and shear modulus were calculated by specific formulas.All results were based on a series of tests conducted by the electronic universal testing machine and dial indicator . Bamboo plywood (including directed and nondirected) has satisfactory flexural and shear properties during the tests.Before tests,two surfaces of test block were defined as free surface and cutting surface corresponding to two loading directions.In different loading directions ,test block with the same size may behave different midspan deflections under the same cyclic load. Based on measured datas , the related mechanical modulus were gained , and the failure modes of bamboo plywood were discussed .

Abstract: Five-layer biaxial weft knitted (FBWK) fabric is one kind of multilayered biaxial weft knitted (MBWK) fabric. FBWK fabric is made of carbon fiber as inserted yarns and stitched with polyester yarns, and it has been impregnated with epoxy via resin transfer molding (RTM) technique to manufacture the composite plates. The bending properties of the FBWK fabric reinforced composite are studied with the three-point bending test method. The bending properties of the FBWK fabric reinforced composite materials with different fiber volume fraction have been investigated. The results show that the relationship between bending load and deflection is obviously linear before reaching the maximum load. Within a certain range, the bending strength of this kind of composites increases with the fiber volume fraction increasing. When the fiber volume fraction is 57%, the bending strength is 1051.4 MPa.

Abstract: In this paper, three-layer biaxial weft knitted fabric(TBWK) made of carbon fiber as inserted yarns and polyester yarns as knitted yarns , which is a kind of non-crimp fabric, has been impregnated with epoxy via RTM technique. The bending properties of the TBWK fabric reinforced composite materials with different fiber volume fraction have been investigated. The bending strength of TBWK reinforced composites with fiber volume fraction of 48.8% can reach 821.1 MPa. The results show that this kind of composites has good bending properties, and load - deflection curve shows obvious linear features.

Abstract: Shape Memory Polymer Composites (SMPC) is a compound of resin matrix and fiber reinforced material. It has advantages of lager restoring force, lower density, higher stiffness and strength. The stiffness of laminate and thin walled tube using SMPC materials was discussed in this paper. Experiment was made to verify the different structures influences on deployment at the same temperature. The initial stiffness of laminate decrease at 40°C to 50°C, but that’s for tube was about 70°C to 80°C. It illustrated that the structural influence should also be concerned except the Tg. At the last of the paper, stiffness of laminate, tube and semicircular were calculated respectively to see the influence of structure at normal temperature.

Abstract: The effect of span-to-thickness ratio (L/h) on the bending modulus was investigated in warp, 45°, 67.5° and weft directions in woven glass fiber reinforced polyester laminates. Using classical beam theory the results of the bending tests carried out for L/h = 5,..,50 were extended to the total range of definition (0≤L/h<∞) by applying rational fractional and exponential fractional functions. The extensions take the asymptotic behavior of the bending test for L/h = 0 and L/h = ∞ in account while providing the best fitting to the measured data. It has been shown that the exponential fractional estimations give better results regarding the form of functions that is independent from the directions.