[Objectives] This study was conducted to develop a polyurea elastomer which can be sprayed on the surface of expanded polystyrene (EPS) floating balls, so as to improve the surface strength and service life of the flo...[Objectives] This study was conducted to develop a polyurea elastomer which can be sprayed on the surface of expanded polystyrene (EPS) floating balls, so as to improve the surface strength and service life of the floating balls. [Methods] The effects of the types and amounts of isocyanate, chain extenders and polyether polyols on the gelation rate, adhesion and wear resistance of polyurea elastomer were investigated, and it was finally determined the preparation process of polyurea elastomer using liquid isophorone diisocyanate (IPDI) and amino-terminated polyether (D2000) as the main raw materials, dimethylthiotoluene diamine (E300) as the chain extender and silica as the wear resistance modifier through two-step solution polymerization of prepolymerization and chain extension. [Results] The physical properties and chemical resistance tests of spray polyurea elastomer showed that it had good physical properties and acid and alkali resistance, and could meet the requirements of spraying and protection of EPS floating ball surface in marine environment. [Conclusions] Polyurea elastomer coating can improve the aging resistance, wear resistance and acid and alkali resistance of EPS floating balls, and prevent them from being fragile and floating randomly to form marine floating garbage which results in "white pollution".展开更多
电动助力转向(electric power steering,EPS)系统是车辆常用的转向执行器,其失效将严重影响驾乘人员的安全。为提高EPS系统的安全性与可靠性,基于功能安全标准建立EPS系统安全冗余机制:基于ISO26262对EPS系统进行研究,通过相关项定义、...电动助力转向(electric power steering,EPS)系统是车辆常用的转向执行器,其失效将严重影响驾乘人员的安全。为提高EPS系统的安全性与可靠性,基于功能安全标准建立EPS系统安全冗余机制:基于ISO26262对EPS系统进行研究,通过相关项定义、危害分析与风险评估(HARA),得到系统的功能安全目标与需求,并对其进行分配;设计EPS系统架构、容错机制,以提高系统的安全性;最后,对所设计的安全冗余机制进行台架试验。结果表明,在单侧桥驱芯片故障、单侧电机位置传感器故障、双侧电机位置传感器故障等故障注入的情况下,系统能够实现预期响应,满足功能安全目标,验证了所设计安全冗余机制的有效性。展开更多
基金Supported by Special Project for High-quality Development of Marine Services and Fishery in Fujian Province in 2023(FJHY-YYKJ-2023-1-3)。
文摘[Objectives] This study was conducted to develop a polyurea elastomer which can be sprayed on the surface of expanded polystyrene (EPS) floating balls, so as to improve the surface strength and service life of the floating balls. [Methods] The effects of the types and amounts of isocyanate, chain extenders and polyether polyols on the gelation rate, adhesion and wear resistance of polyurea elastomer were investigated, and it was finally determined the preparation process of polyurea elastomer using liquid isophorone diisocyanate (IPDI) and amino-terminated polyether (D2000) as the main raw materials, dimethylthiotoluene diamine (E300) as the chain extender and silica as the wear resistance modifier through two-step solution polymerization of prepolymerization and chain extension. [Results] The physical properties and chemical resistance tests of spray polyurea elastomer showed that it had good physical properties and acid and alkali resistance, and could meet the requirements of spraying and protection of EPS floating ball surface in marine environment. [Conclusions] Polyurea elastomer coating can improve the aging resistance, wear resistance and acid and alkali resistance of EPS floating balls, and prevent them from being fragile and floating randomly to form marine floating garbage which results in "white pollution".
文摘电动助力转向(electric power steering,EPS)系统是车辆常用的转向执行器,其失效将严重影响驾乘人员的安全。为提高EPS系统的安全性与可靠性,基于功能安全标准建立EPS系统安全冗余机制:基于ISO26262对EPS系统进行研究,通过相关项定义、危害分析与风险评估(HARA),得到系统的功能安全目标与需求,并对其进行分配;设计EPS系统架构、容错机制,以提高系统的安全性;最后,对所设计的安全冗余机制进行台架试验。结果表明,在单侧桥驱芯片故障、单侧电机位置传感器故障、双侧电机位置传感器故障等故障注入的情况下,系统能够实现预期响应,满足功能安全目标,验证了所设计安全冗余机制的有效性。
