An artificially accelerated alternation of aging and seawater erosion test of rubber materials used in lead rubber bearing(LRB)was performed,mainly to study the time-varying laws of rubber materials mechanical propert...An artificially accelerated alternation of aging and seawater erosion test of rubber materials used in lead rubber bearing(LRB)was performed,mainly to study the time-varying laws of rubber materials mechanical properties.Time-varying laws of the Mooney–Rivlin and Neo-Hookean constitutive parameters of rubber materials under the alternation of aging and seawater erosion were also analyzed.Results indicate that the rubber material mechanical properties were significantly affected by alternation of aging and seawater erosion.Hardness and elongation stress increased exponentially with test time.And 120 days after the test,the hardness increased by 14%,the maximum percentage increase in stress of 124.76%occurred at 100%constant elongation and the minimum percentage increase in stress of 68.32%occurred at 300%constant elongation;Tensile strength and elongation at break decreased by 44.96%and 53.09%.Besides,constitutive parameters of Mooney–Rivlin and Neo-Hookean all changed greatly with test duration.Finally,time-varying laws of constitutive parameters were verified by comparing the simulated and experimental results of the lead rubber bearing’s stiffness.Research results are of great significance to the seismic performance research and life-cycle performance analysis of offshore traffic engineering such as cross-sea bridges and bridges in the marine environment.展开更多
The effect of deformation of porous material on infiltrative performance is investigated. Based on Darcy theory and Boit principle, the Reynolds equation and mathematical expression of deformable metal rubber （MR） m...The effect of deformation of porous material on infiltrative performance is investigated. Based on Darcy theory and Boit principle, the Reynolds equation and mathematical expression of deformable metal rubber （MR） material under laminar flow are obtained according to the change of porosity of metal rubber. It is shown that the throttle of MR material is dependent on its porosity and diameter of metal wires. It will be of great value for the application of MR in throttle field.展开更多
The first resonant(anti-resonant)frequency and sound absorption coefficient of metal rubber(MR) material are theoretically studied with hard backed samples and with air layer.The equations of the first resonant and an...The first resonant(anti-resonant)frequency and sound absorption coefficient of metal rubber(MR) material are theoretically studied with hard backed samples and with air layer.The equations of the first resonant and anti-resonant frequencies of MR are deduced from the undamped propagation characteristics of porous material.The first resonant and anti-resonance sound absorption coefficients are induced according to the theoretical formula for the acoustic characteristic parameters of MR,and the former is modified while the energy consumption at resonance is taken into consideration.The good agreement between the calculation results of these resonant sound absorption parameters and the experimental results verifies the effectiveness of this calculation method for the performance evaluation of MR as a sound absorption material.展开更多
A material-structure integrated design method is proposed in this paper,with which micropillar and microwedge arrayed surfaces are fabricated based on a novel nanoparticlereinforced silicone rubber composite(NRSRC)wit...A material-structure integrated design method is proposed in this paper,with which micropillar and microwedge arrayed surfaces are fabricated based on a novel nanoparticlereinforced silicone rubber composite(NRSRC)with high mechanical strength and strong surface adhesion.It is found that the micropillar-arrayed surface and the microwedgearrayed surface show a normal adhesive strength of 50.9 kPa and a shear adhesive strength of 137.3 kPa,respectively,which are much higher than those of previously reported adhesive surfaces made by pure soft polymers.Furthermore,the micro-wedgearrayed surface shows not only strong and stable adhe-sion on rough and smooth substrates but also an obvious anisotropy in the adhesion property.The latter consequently leads to an easy control of the attachment/detachment switch,which is evidenced by a mechanical gripper with a microwedged surface.Therefore,firmly picking up and easily releasing a heavy glass plate can be realized.All these results demonstrate the apparent advantages of the present compo-sitebased fibrillar surfaces in achieving reliable and reversible adhesion and should have promising applications for manufac-turing advanced adhesive devices,such as mechanical fixtures,portable climbing equipment and space robots.展开更多
基金This work was supported by the Programme for National Natural Science Foundation of China(52078150,51878196)National Key R&D Program of China(2019YFE0112500)2019 Guangzhou University Full-Time Graduate“Basic Innovation”Project(2019GDJC-D11).
文摘An artificially accelerated alternation of aging and seawater erosion test of rubber materials used in lead rubber bearing(LRB)was performed,mainly to study the time-varying laws of rubber materials mechanical properties.Time-varying laws of the Mooney–Rivlin and Neo-Hookean constitutive parameters of rubber materials under the alternation of aging and seawater erosion were also analyzed.Results indicate that the rubber material mechanical properties were significantly affected by alternation of aging and seawater erosion.Hardness and elongation stress increased exponentially with test time.And 120 days after the test,the hardness increased by 14%,the maximum percentage increase in stress of 124.76%occurred at 100%constant elongation and the minimum percentage increase in stress of 68.32%occurred at 300%constant elongation;Tensile strength and elongation at break decreased by 44.96%and 53.09%.Besides,constitutive parameters of Mooney–Rivlin and Neo-Hookean all changed greatly with test duration.Finally,time-varying laws of constitutive parameters were verified by comparing the simulated and experimental results of the lead rubber bearing’s stiffness.Research results are of great significance to the seismic performance research and life-cycle performance analysis of offshore traffic engineering such as cross-sea bridges and bridges in the marine environment.
基金This project is supported by National Natural Science Foundation of China (No.50075017)Municipal Youth Foundation of Harbin, China(No.2003AFQXJ035).
文摘The effect of deformation of porous material on infiltrative performance is investigated. Based on Darcy theory and Boit principle, the Reynolds equation and mathematical expression of deformable metal rubber （MR） material under laminar flow are obtained according to the change of porosity of metal rubber. It is shown that the throttle of MR material is dependent on its porosity and diameter of metal wires. It will be of great value for the application of MR in throttle field.
基金Supported by the National Natural Science Foundation of China(Grant No.50675042)
文摘The first resonant(anti-resonant)frequency and sound absorption coefficient of metal rubber(MR) material are theoretically studied with hard backed samples and with air layer.The equations of the first resonant and anti-resonant frequencies of MR are deduced from the undamped propagation characteristics of porous material.The first resonant and anti-resonance sound absorption coefficients are induced according to the theoretical formula for the acoustic characteristic parameters of MR,and the former is modified while the energy consumption at resonance is taken into consideration.The good agreement between the calculation results of these resonant sound absorption parameters and the experimental results verifies the effectiveness of this calculation method for the performance evaluation of MR as a sound absorption material.
基金NSFC through Grants(No.12032004,No.12293000,No.12293002,No.12272043)Natural Science Foundation of Henan(No.202300410088)as well as Innovation Demonstration Project of Henan(No.201111211400).
文摘A material-structure integrated design method is proposed in this paper,with which micropillar and microwedge arrayed surfaces are fabricated based on a novel nanoparticlereinforced silicone rubber composite(NRSRC)with high mechanical strength and strong surface adhesion.It is found that the micropillar-arrayed surface and the microwedgearrayed surface show a normal adhesive strength of 50.9 kPa and a shear adhesive strength of 137.3 kPa,respectively,which are much higher than those of previously reported adhesive surfaces made by pure soft polymers.Furthermore,the micro-wedgearrayed surface shows not only strong and stable adhe-sion on rough and smooth substrates but also an obvious anisotropy in the adhesion property.The latter consequently leads to an easy control of the attachment/detachment switch,which is evidenced by a mechanical gripper with a microwedged surface.Therefore,firmly picking up and easily releasing a heavy glass plate can be realized.All these results demonstrate the apparent advantages of the present compo-sitebased fibrillar surfaces in achieving reliable and reversible adhesion and should have promising applications for manufac-turing advanced adhesive devices,such as mechanical fixtures,portable climbing equipment and space robots.
