The bamboo powder/polycaprolactone composites (BPPC) were prepared by torque-rheometer to investigate the effects of recipes and processing conditions on the rheological properties of BPPC. The morphological behavior ...The bamboo powder/polycaprolactone composites (BPPC) were prepared by torque-rheometer to investigate the effects of recipes and processing conditions on the rheological properties of BPPC. The morphological behavior and mechanical properties of BPPC were also studied. Results showed that the optimum recipe for composite materials is composed of 70% of polycaprolactone, 30% of bamboo powder according to volume, 1.6 % of aluminate coupling agent, 1.2% of stearic acid, and 2% of paraffin to bamboo powder according to mass ratio. The optimum processing condition parameters were determined as the rotational speed at 50 r·min-1 and the temperature at 100oC for BPPC. The BPPC (containing 30 copies bamboo powder) possessed eminent interfacial compatibility and mechanical properties of BPPC.展开更多
The interface of slab track laid in cold regions is prone to debonding under the coupling of freeze-thaw cyclesand temperature loads.Based on the composite specimen tests,the parameters of cohesive zone model were obt...The interface of slab track laid in cold regions is prone to debonding under the coupling of freeze-thaw cyclesand temperature loads.Based on the composite specimen tests,the parameters of cohesive zone model were obtained andused in a simulation model of CRTS III prefabricated slab track to study the interlayer damage.The results show that 1)the digital image correlation(DIC)technique can accurately capture the strain field changes on the interface of compositespecimens under splitting and shear loading;2)when the temperature gradient is−40℃/m−60℃/m,the interfacedamage of the slab track is minimal and presents different patterns of expansion under positive and negative temperaturegradients,each corresponding to damage of the cohesive element dominated by shear stress and normal tensile stress,respectively;3)the reduction of the elastic modulus at the concrete base after freeze-thaw inhibits interface damage andleads to a higher starting temperature gradient load,but cracking can occur on the concrete base after 150 freeze-thaws.For this reason,in the light of damage control of both the interface and concrete base,the elastic modulus of the concretebase is 54%or over that without freeze-thaw cycles.展开更多
基金funded by Natural Science Founda-tion of Fujian Province (No. 2008J0227)Science and TechnologyOffice of Fujian Province (No. 2007F5030)
文摘The bamboo powder/polycaprolactone composites (BPPC) were prepared by torque-rheometer to investigate the effects of recipes and processing conditions on the rheological properties of BPPC. The morphological behavior and mechanical properties of BPPC were also studied. Results showed that the optimum recipe for composite materials is composed of 70% of polycaprolactone, 30% of bamboo powder according to volume, 1.6 % of aluminate coupling agent, 1.2% of stearic acid, and 2% of paraffin to bamboo powder according to mass ratio. The optimum processing condition parameters were determined as the rotational speed at 50 r·min-1 and the temperature at 100oC for BPPC. The BPPC (containing 30 copies bamboo powder) possessed eminent interfacial compatibility and mechanical properties of BPPC.
基金Project(52425213)supported by the National Science Fund for Distinguished Young Scholars of ChinaProjects(52278461,52308467)supported by the National Natural Science Foundation of China+1 种基金Projects(2021YFF0502100,2021YFB2600900)supported by the National Key R&D Program of ChinaProject(2022JDTD0015)supported by the Sichuan Province Youth Science and Technology Innovation Team,China。
文摘The interface of slab track laid in cold regions is prone to debonding under the coupling of freeze-thaw cyclesand temperature loads.Based on the composite specimen tests,the parameters of cohesive zone model were obtained andused in a simulation model of CRTS III prefabricated slab track to study the interlayer damage.The results show that 1)the digital image correlation(DIC)technique can accurately capture the strain field changes on the interface of compositespecimens under splitting and shear loading;2)when the temperature gradient is−40℃/m−60℃/m,the interfacedamage of the slab track is minimal and presents different patterns of expansion under positive and negative temperaturegradients,each corresponding to damage of the cohesive element dominated by shear stress and normal tensile stress,respectively;3)the reduction of the elastic modulus at the concrete base after freeze-thaw inhibits interface damage andleads to a higher starting temperature gradient load,but cracking can occur on the concrete base after 150 freeze-thaws.For this reason,in the light of damage control of both the interface and concrete base,the elastic modulus of the concretebase is 54%or over that without freeze-thaw cycles.
