To improve the manufacture efficiency and promote the application of composites in the automobile industry, a new composite forming method, thermal stamping, was discussed to form composite parts directly. Experiments...To improve the manufacture efficiency and promote the application of composites in the automobile industry, a new composite forming method, thermal stamping, was discussed to form composite parts directly. Experiments on two typical stamping processes, thermal bending and thermal deep drawing, were conducted to investigate the forming behavior of composite sheets and analyze the influence of forming temperature on the formed composite part. Experimental results show that the locking angle for woven composite is about 30°. The bending load is smaller than 5 N in the stamping process and decreases with the increase of temperature. The optimal temperature to form the carbon fiber composite is 170 ℃. The die temperature distribution and the deformation of composite sheet were simulated by FEA software ABAQUS. To investigate the fiber movement of carbon woven fabric during stamping, the two-node three-dimension linear Truss unit T2D3 was chosen as the fiber element. The simulation results have a good agreement to the experimental results.展开更多
Bending tests were conducted on 23 ferrocement slab specimens with steel meshes and continuous CFRP fibers. Two, or three, or four CFRP slices are gathered as a rope and hence these ropes are arranged to form a grid t...Bending tests were conducted on 23 ferrocement slab specimens with steel meshes and continuous CFRP fibers. Two, or three, or four CFRP slices are gathered as a rope and hence these ropes are arranged to form a grid tied to a skeletal frame. The three patterns of slice reinforcement were used to reinforce cementitious slabs with or without conventional wire mesh reinforcement. The slabs were square and simply supported at their periphery with a clear span of 400 mm, and concentrically patch loaded to failure. For specimens designed to fail in flexure, the specimens reinforced with CFRP slices showed a smoother load deflection response and higher flexural capacity. For slabs designed to fail in punching shear, adding CFRP slices showed significant improvement in the ultimate shear capacity and ductility over reference specimens. Well distributed fine cracks of smaller width than control specimens were developed and no matrix spalling was observed.展开更多
This paper demonstrates the possibility of combining both glass and carbon FRP （Fibre Reinforced Polymer） composite materials with a low-cost construction material （i.e. concrete） in a hybrid system that brings hi...This paper demonstrates the possibility of combining both glass and carbon FRP （Fibre Reinforced Polymer） composite materials with a low-cost construction material （i.e. concrete） in a hybrid system that brings higher performance levels to the design of lightweight, corrosion resistant, yet inexpensive beams providing acceptable structural properties. The objective of the research is to investigate the behaviour of a hybrid composite section under flexure. The hybrid section consists of a top concrete slab, Glass Fibre Reinforced Polymer （GFRP） beam section and Carbon Fibre Reinforced Polymer （CFRP） laminate on the extreme underside. This maximizes the benefits of each material, that is： high tensile strength of CFRP, compressive strength and low cost of concrete, light weight and lower cost of GFRP, and high corrosion resistance of all components. Three beam samples were manufactured and tested to failure while monitoring deflections and strains. By adding CFRP layers under the concrete-GFRP composite beam increases the bending strength and reduces the deflection. The most important factor in the proposed strengthening technique of GFRP-concrete composite beams by using CFRP is the adhesive material that bonds the CFRP to the GFRP. Any weakness in CFRP-GFRP bond may cause brittle failure of the beam. The study results indicate the benefits of using hybrid FRP-concrete beams to increase flexural load carrying capacity and beam stiffness and provide a numerical model that can be further developed to model more advanced material arrangements in the future. The outcome of this research provides information for both designers and researchers in the field of FRP composites.展开更多
The investigating of the hot press process parameters on the flexural properties of LVL （Laminated Veneer Lumber） reinforced composites derived from rubber wood veneer reinforced with fiber glass woven and epoxy adh...The investigating of the hot press process parameters on the flexural properties of LVL （Laminated Veneer Lumber） reinforced composites derived from rubber wood veneer reinforced with fiber glass woven and epoxy adhesive were performed via the DOE （design of experimental） approach. It was discovered that pressure was the most significantly and negatively effect on the product properties. Enhancing in the mechanical properties was related to decrease the processing pressure. Beside, press time was also significantly and positively effect. Although time was not clearly reflect from the mechanical results, but it was detected from the ANOVA （analysis of variance）results. The mechanical properties were increased with increasing compression time. From the results, the optimal condition to maximize mechanical properties was assumed at low pressure, 15 bars, low temperature, 70℃, and long time, 60 mins. The durability testing including screw nail withdrawal strength, water absorption, and termite resistance of LVL reinforced composite were also studied. The results are shown that the LVL wood has superior properties when compare with solid woods. It was found the withdrawal strength of LVL reinforce composite was higher than the solid woods. As expected that solid woods, except eucalyptus, had low water absorption resistance as it more hygroscopic corresponded to LVL reinforced wood. Also solid woods, except teal（, had low resistance to termite attack. Therefore, LVL reinforced was the best candidate by mean of durability properties compared to solid wood.展开更多
Light-weight composite panels were manufactured using kenaf core particles as core material and kenaf bast fiber-woven sheets as top and bottom surfaces. Methylene diphenyldiisocyanate (MDI) resin was used as the adhe...Light-weight composite panels were manufactured using kenaf core particles as core material and kenaf bast fiber-woven sheets as top and bottom surfaces. Methylene diphenyldiisocyanate (MDI) resin was used as the adhesive with the resin content of 4% for core particles and 50 g/m2 for bast fiber- woven sheets. The target board densities were set at 0.35, 0.45 and 0.55 g/cm3. The composite panels were evaluated with Japanese Industrial Standard for Particleboards (JIS A 5908- 2003).The results show that the composite panel has high modulus of rupture and internal bonding strength. The properties of 0.45 g/cm3 density composite panel are: MOR 20.4 MPa, MOE 1.94 MPa, IB 0.36 MPa, WA142%, TS 21%. Kenaf is a good raw material for making light-weight composite panels.展开更多
基金Project(51375369)supported by the National Natural Science Foundation of ChinaProject(SYG201137)supported by the Science and Technology Development Program of Suzhou,China
文摘To improve the manufacture efficiency and promote the application of composites in the automobile industry, a new composite forming method, thermal stamping, was discussed to form composite parts directly. Experiments on two typical stamping processes, thermal bending and thermal deep drawing, were conducted to investigate the forming behavior of composite sheets and analyze the influence of forming temperature on the formed composite part. Experimental results show that the locking angle for woven composite is about 30°. The bending load is smaller than 5 N in the stamping process and decreases with the increase of temperature. The optimal temperature to form the carbon fiber composite is 170 ℃. The die temperature distribution and the deformation of composite sheet were simulated by FEA software ABAQUS. To investigate the fiber movement of carbon woven fabric during stamping, the two-node three-dimension linear Truss unit T2D3 was chosen as the fiber element. The simulation results have a good agreement to the experimental results.
文摘Bending tests were conducted on 23 ferrocement slab specimens with steel meshes and continuous CFRP fibers. Two, or three, or four CFRP slices are gathered as a rope and hence these ropes are arranged to form a grid tied to a skeletal frame. The three patterns of slice reinforcement were used to reinforce cementitious slabs with or without conventional wire mesh reinforcement. The slabs were square and simply supported at their periphery with a clear span of 400 mm, and concentrically patch loaded to failure. For specimens designed to fail in flexure, the specimens reinforced with CFRP slices showed a smoother load deflection response and higher flexural capacity. For slabs designed to fail in punching shear, adding CFRP slices showed significant improvement in the ultimate shear capacity and ductility over reference specimens. Well distributed fine cracks of smaller width than control specimens were developed and no matrix spalling was observed.
文摘This paper demonstrates the possibility of combining both glass and carbon FRP （Fibre Reinforced Polymer） composite materials with a low-cost construction material （i.e. concrete） in a hybrid system that brings higher performance levels to the design of lightweight, corrosion resistant, yet inexpensive beams providing acceptable structural properties. The objective of the research is to investigate the behaviour of a hybrid composite section under flexure. The hybrid section consists of a top concrete slab, Glass Fibre Reinforced Polymer （GFRP） beam section and Carbon Fibre Reinforced Polymer （CFRP） laminate on the extreme underside. This maximizes the benefits of each material, that is： high tensile strength of CFRP, compressive strength and low cost of concrete, light weight and lower cost of GFRP, and high corrosion resistance of all components. Three beam samples were manufactured and tested to failure while monitoring deflections and strains. By adding CFRP layers under the concrete-GFRP composite beam increases the bending strength and reduces the deflection. The most important factor in the proposed strengthening technique of GFRP-concrete composite beams by using CFRP is the adhesive material that bonds the CFRP to the GFRP. Any weakness in CFRP-GFRP bond may cause brittle failure of the beam. The study results indicate the benefits of using hybrid FRP-concrete beams to increase flexural load carrying capacity and beam stiffness and provide a numerical model that can be further developed to model more advanced material arrangements in the future. The outcome of this research provides information for both designers and researchers in the field of FRP composites.
文摘The investigating of the hot press process parameters on the flexural properties of LVL （Laminated Veneer Lumber） reinforced composites derived from rubber wood veneer reinforced with fiber glass woven and epoxy adhesive were performed via the DOE （design of experimental） approach. It was discovered that pressure was the most significantly and negatively effect on the product properties. Enhancing in the mechanical properties was related to decrease the processing pressure. Beside, press time was also significantly and positively effect. Although time was not clearly reflect from the mechanical results, but it was detected from the ANOVA （analysis of variance）results. The mechanical properties were increased with increasing compression time. From the results, the optimal condition to maximize mechanical properties was assumed at low pressure, 15 bars, low temperature, 70℃, and long time, 60 mins. The durability testing including screw nail withdrawal strength, water absorption, and termite resistance of LVL reinforced composite were also studied. The results are shown that the LVL wood has superior properties when compare with solid woods. It was found the withdrawal strength of LVL reinforce composite was higher than the solid woods. As expected that solid woods, except eucalyptus, had low water absorption resistance as it more hygroscopic corresponded to LVL reinforced wood. Also solid woods, except teal（, had low resistance to termite attack. Therefore, LVL reinforced was the best candidate by mean of durability properties compared to solid wood.
基金Supported by the talent fund of the Central South University of Forestry and Technology.
文摘Light-weight composite panels were manufactured using kenaf core particles as core material and kenaf bast fiber-woven sheets as top and bottom surfaces. Methylene diphenyldiisocyanate (MDI) resin was used as the adhesive with the resin content of 4% for core particles and 50 g/m2 for bast fiber- woven sheets. The target board densities were set at 0.35, 0.45 and 0.55 g/cm3. The composite panels were evaluated with Japanese Industrial Standard for Particleboards (JIS A 5908- 2003).The results show that the composite panel has high modulus of rupture and internal bonding strength. The properties of 0.45 g/cm3 density composite panel are: MOR 20.4 MPa, MOE 1.94 MPa, IB 0.36 MPa, WA142%, TS 21%. Kenaf is a good raw material for making light-weight composite panels.
