Ice crossings have been used for several reasons.First,due to the active development of the Arctic shelf,supplies and minerals are provided and transferred on special transports on the surface of ice covers.Second,ice...Ice crossings have been used for several reasons.First,due to the active development of the Arctic shelf,supplies and minerals are provided and transferred on special transports on the surface of ice covers.Second,ice crossings across rivers are used to reduce the length of transport routes.Traditional methods of increasing the load bearing capacity of ice are ice freezing from above,ice freezing from below,and ice strengthening through a wooden copepod flooring.Practical experience shows that the physical and mechanical properties of ice covers are unreliable and changeable in time and strongly depend on various external factors.Therefore,ice covers should be strengthened through alternative methods.Thus,predicting the bearing capacity of ice crossings and exploring methods for their strengthening are important.In this study,we consider the results of experimental and numerical studies on the bearing and deformation capacity of ice beams upon destruction from pure bending.Under pure bending,ice breaks down in the ice crossing when transports move along it.Tests were carried out with a specified reinforcement scheme.The results of the model experiments were compared with numerical calculations in the ANSYS software package.Experiments on ice beams reinforced with various composite materials were also performed.Destruction of samples in all cases occurred as a result of the formation of extensive cracks in the ice caused by the bending moment in the middle of the beam span.Based on the experimental and numerical research results,the use of a surface reinforcement in ice with various materials can increase the bearing capacity from 65%to 99%for this reinforcement scheme.展开更多
Mechanical alloying method was applied to fabricate coating with amorphous structure on pure Cu substrate.The microstructure,the phase composition and the mechanical properties including microhardness and wear resista...Mechanical alloying method was applied to fabricate coating with amorphous structure on pure Cu substrate.The microstructure,the phase composition and the mechanical properties including microhardness and wear resistance of the coating were,respectively,characterized and analyzed.The results show that the coating is rough but continuous.It has favorable adhesion to the substrate.The coating is made up of an inner composite layer and an outer amorphous layer.The microhardness and the wear resistance of the pure Cu substrate are improved because of the bilayer structure.The formation mechanism of the coating was discussed.The as-synthesized coating is considered to be effective to strengthen the surface of pure Cu substrate.展开更多
文摘Ice crossings have been used for several reasons.First,due to the active development of the Arctic shelf,supplies and minerals are provided and transferred on special transports on the surface of ice covers.Second,ice crossings across rivers are used to reduce the length of transport routes.Traditional methods of increasing the load bearing capacity of ice are ice freezing from above,ice freezing from below,and ice strengthening through a wooden copepod flooring.Practical experience shows that the physical and mechanical properties of ice covers are unreliable and changeable in time and strongly depend on various external factors.Therefore,ice covers should be strengthened through alternative methods.Thus,predicting the bearing capacity of ice crossings and exploring methods for their strengthening are important.In this study,we consider the results of experimental and numerical studies on the bearing and deformation capacity of ice beams upon destruction from pure bending.Under pure bending,ice breaks down in the ice crossing when transports move along it.Tests were carried out with a specified reinforcement scheme.The results of the model experiments were compared with numerical calculations in the ANSYS software package.Experiments on ice beams reinforced with various composite materials were also performed.Destruction of samples in all cases occurred as a result of the formation of extensive cracks in the ice caused by the bending moment in the middle of the beam span.Based on the experimental and numerical research results,the use of a surface reinforcement in ice with various materials can increase the bearing capacity from 65%to 99%for this reinforcement scheme.
基金financially supported by the Introduce Talent Special Funding for Scientific Research at Nanjing Tech University(No.39802125)the National Natural Science Foundation of China(No.51475232)。
文摘Mechanical alloying method was applied to fabricate coating with amorphous structure on pure Cu substrate.The microstructure,the phase composition and the mechanical properties including microhardness and wear resistance of the coating were,respectively,characterized and analyzed.The results show that the coating is rough but continuous.It has favorable adhesion to the substrate.The coating is made up of an inner composite layer and an outer amorphous layer.The microhardness and the wear resistance of the pure Cu substrate are improved because of the bilayer structure.The formation mechanism of the coating was discussed.The as-synthesized coating is considered to be effective to strengthen the surface of pure Cu substrate.