In this study, several kinds of flexible protective materials sprayed with polyurea elastomers （hereinafter referred to as polyurea elastomer protective material） were adopted to meet the abrasion resistance require...In this study, several kinds of flexible protective materials sprayed with polyurea elastomers （hereinafter referred to as polyurea elastomer protective material） were adopted to meet the abrasion resistance requirement of hydraulic structures, and their abrasion resistances against the water flow with suspended load or bed load were studied systematically through tests. Natural basalt stones were adopted as the abrasive for simulation of the abrasion effect of the water flow with bed load, and test results indicate that the basalt stone is suitable for use in the abrasion resistance test of the flexible protective material. The wear process of the polyurea elastomer protective material is stable, and the wear loss is linear with the time of abrasion. If the wear thickness is regarded as the abrasion resistance evaluation factor, the abrasion resistance of the 351 pure polyurea is about twice those of pure polyurea with a high level of hardness and aliphatic polyurea, and over five times that of high-performance abrasion-resistant concrete under the abrasion of the water flow with suspended load. It is also about 50 times that of high-performance abrasion-resistant concrete under the abrasion of the water flow with bed load. Overall, the abrasion resistance of pure polyurea presented a decreasing trend with increasing hardness. Pure polyurea with a Shore hardness of D30 has the best abrasion resistance, which is 60 to 70 times that of high-performance abrasion-resistant concrete under the abrasion of the water flow with bed load, and has been recommended, among the five kinds of pure polyurea materials with different hardness, in anti-abrasion protection of hydraulic structures.展开更多
In this paper, we tried to present a qualitative correlation, based on extensive experimental trials between the value and the evolution of the friction coefficient, wear and contact temperature in the case of linear ...In this paper, we tried to present a qualitative correlation, based on extensive experimental trials between the value and the evolution of the friction coefficient, wear and contact temperature in the case of linear dry contact, thermoplastic material reinforced with SGF （short glass fibres） and various steel surfaces. We tried, believing successfully, the graphic illustration of the evolution of the steel surface wear and of the contact temperature, depending on the friction coefficient. It was analyzed in detail the influence of the normal load and sliding speed, but also of the metallic surface roughness on the friction coefficient.展开更多
In this paper we tried to present a qualitative correlation,based on extensive experimental determinations between the value and the evolution of the friction coefficient,wear,and contact temperature,in the case of li...In this paper we tried to present a qualitative correlation,based on extensive experimental determinations between the value and the evolution of the friction coefficient,wear,and contact temperature,in the case of linear dry contact,for thermoplastic material reinforced with short glass fibers(SGF)and various steel surfaces.The aim was to highlight the evolution of the wear process depending on the evolution of the friction coefficient.As a result,it was possible to graphically illustrate the evolution of the friction coefficient and the change of the wear process,emphasizing the abrasive,adhesive and corrosive wear.The evolution of the plastic material transfer function of the contact temperature,namely of the power lost by friction(product between the contact pressure and sliding speed,p and v)was aimed and it was highlighted.It has been demonstrated that in the case of a 30%SGF content it can reach and even exceed contact temperatures very close to the flow limit of the plastic material.We tried,believing successfully,the graphic illustration of the evolution of the steel surface wear and of the contact temperature,depending on the friction coefficient.The influence of the normal load and sliding speed was evaluated in detail,but also the influence of the metallic surface roughness on the friction coefficient was discussed.展开更多
基金supported by the National Natural Science Foundation of China(Grants No.51109143 and 51209144)the Natural Science Foundation of Jiangsu Province(Grant No.BK2011109)the Foundation of Nanjing Hydraulic Research Institute(Grant No.Y113004)
文摘In this study, several kinds of flexible protective materials sprayed with polyurea elastomers （hereinafter referred to as polyurea elastomer protective material） were adopted to meet the abrasion resistance requirement of hydraulic structures, and their abrasion resistances against the water flow with suspended load or bed load were studied systematically through tests. Natural basalt stones were adopted as the abrasive for simulation of the abrasion effect of the water flow with bed load, and test results indicate that the basalt stone is suitable for use in the abrasion resistance test of the flexible protective material. The wear process of the polyurea elastomer protective material is stable, and the wear loss is linear with the time of abrasion. If the wear thickness is regarded as the abrasion resistance evaluation factor, the abrasion resistance of the 351 pure polyurea is about twice those of pure polyurea with a high level of hardness and aliphatic polyurea, and over five times that of high-performance abrasion-resistant concrete under the abrasion of the water flow with suspended load. It is also about 50 times that of high-performance abrasion-resistant concrete under the abrasion of the water flow with bed load. Overall, the abrasion resistance of pure polyurea presented a decreasing trend with increasing hardness. Pure polyurea with a Shore hardness of D30 has the best abrasion resistance, which is 60 to 70 times that of high-performance abrasion-resistant concrete under the abrasion of the water flow with bed load, and has been recommended, among the five kinds of pure polyurea materials with different hardness, in anti-abrasion protection of hydraulic structures.
文摘In this paper, we tried to present a qualitative correlation, based on extensive experimental trials between the value and the evolution of the friction coefficient, wear and contact temperature in the case of linear dry contact, thermoplastic material reinforced with SGF （short glass fibres） and various steel surfaces. We tried, believing successfully, the graphic illustration of the evolution of the steel surface wear and of the contact temperature, depending on the friction coefficient. It was analyzed in detail the influence of the normal load and sliding speed, but also of the metallic surface roughness on the friction coefficient.
基金the Romanian Acad-emy and University of Civil Engineering Bucharest,for its material and technical support offered in order to achieve these researches.
文摘In this paper we tried to present a qualitative correlation,based on extensive experimental determinations between the value and the evolution of the friction coefficient,wear,and contact temperature,in the case of linear dry contact,for thermoplastic material reinforced with short glass fibers(SGF)and various steel surfaces.The aim was to highlight the evolution of the wear process depending on the evolution of the friction coefficient.As a result,it was possible to graphically illustrate the evolution of the friction coefficient and the change of the wear process,emphasizing the abrasive,adhesive and corrosive wear.The evolution of the plastic material transfer function of the contact temperature,namely of the power lost by friction(product between the contact pressure and sliding speed,p and v)was aimed and it was highlighted.It has been demonstrated that in the case of a 30%SGF content it can reach and even exceed contact temperatures very close to the flow limit of the plastic material.We tried,believing successfully,the graphic illustration of the evolution of the steel surface wear and of the contact temperature,depending on the friction coefficient.The influence of the normal load and sliding speed was evaluated in detail,but also the influence of the metallic surface roughness on the friction coefficient was discussed.
