Objective： To evaluate the interface characteristics of the new-designed locking plate （LP） and limited contact-dynamic compression plate （LC-DCP） and compare the fracture healing between LP and LC-DCP in a goat ...Objective： To evaluate the interface characteristics of the new-designed locking plate （LP） and limited contact-dynamic compression plate （LC-DCP） and compare the fracture healing between LP and LC-DCP in a goat tibia fracture model. Methods： Eight-hole LP and LC-DCP were applied to fix fresh goat tibiae in a reproducible manner. The average pressure, force and interface contact area were calculated using Fuji prescale pressure sensitive film interposed among the plate and the bone and image analysis system, Eighthole LP and LC-DCP were applied to each tibia in a goat tibia fracture model. The fracture healing was evaluated by X-ray photography at postoperative 8 weeks. The goats were sacrificed at postoperative 12 weeks. Three-point bending test was conducted in the tibiae. Results： The interface contact of LP system was smaller than that ofLC-DCP （P〈0.05）, while interface contact force of LP system was higher than that of LC-DCP （P〈0.05）. Radiographs revealed that the fracture line disappeared in the LP group, while the fracture line was visible in DCP group at postoperative 8 weeks. At postoperative 12 weeks, the bending strength and bending load of fractured tibia were higher in LP group than in DCP group, respectively.展开更多
The characteristics of asphalt mixtures are associated with the key features of the mixed material when it is not damaged.Two-dimensional(2D) microstructure images of asphalt mixture bending beam specimen were capture...The characteristics of asphalt mixtures are associated with the key features of the mixed material when it is not damaged.Two-dimensional(2D) microstructure images of asphalt mixture bending beam specimen were captured by a CCD camera.After image processing,such as noise elimination,boundary identification,image binarization and vectorization,the images were imported into finite element(FE) software in order to set up the micromechanical finite element(FE) model.The simulation results show that the displacement contours spectrum is not a smooth curve since the mixed material is heterogeneous.Also,the largest strain value exists at the bottom of the specimen between two coarse aggregates,and it is the point where the fracture starts.The stress values of aggregates are larger than those of the asphalt matrix.Different from the strain of asphalt matrix,the strain of aggregates is close to zero because the aggregates have higher capability to resist self-deformation.The difference in deformation between aggregate and asphalt matrix can lead to an interface crack as a final result.All these results can be improved by three-point bending test of asphalt mixture beam.展开更多
文摘Objective： To evaluate the interface characteristics of the new-designed locking plate （LP） and limited contact-dynamic compression plate （LC-DCP） and compare the fracture healing between LP and LC-DCP in a goat tibia fracture model. Methods： Eight-hole LP and LC-DCP were applied to fix fresh goat tibiae in a reproducible manner. The average pressure, force and interface contact area were calculated using Fuji prescale pressure sensitive film interposed among the plate and the bone and image analysis system, Eighthole LP and LC-DCP were applied to each tibia in a goat tibia fracture model. The fracture healing was evaluated by X-ray photography at postoperative 8 weeks. The goats were sacrificed at postoperative 12 weeks. Three-point bending test was conducted in the tibiae. Results： The interface contact of LP system was smaller than that ofLC-DCP （P〈0.05）, while interface contact force of LP system was higher than that of LC-DCP （P〈0.05）. Radiographs revealed that the fracture line disappeared in the LP group, while the fracture line was visible in DCP group at postoperative 8 weeks. At postoperative 12 weeks, the bending strength and bending load of fractured tibia were higher in LP group than in DCP group, respectively.
基金supported by the National Natural Science Foundation of China (Grant No. 11162010)the Inner Mongolia Natural Science Foundation (Grant No. 2009MS0701)
文摘The characteristics of asphalt mixtures are associated with the key features of the mixed material when it is not damaged.Two-dimensional(2D) microstructure images of asphalt mixture bending beam specimen were captured by a CCD camera.After image processing,such as noise elimination,boundary identification,image binarization and vectorization,the images were imported into finite element(FE) software in order to set up the micromechanical finite element(FE) model.The simulation results show that the displacement contours spectrum is not a smooth curve since the mixed material is heterogeneous.Also,the largest strain value exists at the bottom of the specimen between two coarse aggregates,and it is the point where the fracture starts.The stress values of aggregates are larger than those of the asphalt matrix.Different from the strain of asphalt matrix,the strain of aggregates is close to zero because the aggregates have higher capability to resist self-deformation.The difference in deformation between aggregate and asphalt matrix can lead to an interface crack as a final result.All these results can be improved by three-point bending test of asphalt mixture beam.
