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改善桥梁加固混凝土性能的研究 被引量:5
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作者 何燕 张雄 +1 位作者 张永娟 张悦然 《材料导报》 EI CAS CSCD 北大核心 2012年第12期129-132,共4页
在定义混凝土贯入阻力值与凝结初期、中期及后期对应关系基础上,利用超声法对混凝土凝结阶段受扰动后强度变化进行分析,并对桥梁加固混凝土的抗扰动机制进行研究;在此基础上,利用自制调凝型功能外加剂、抗裂增韧外加剂、自愈合功能外加... 在定义混凝土贯入阻力值与凝结初期、中期及后期对应关系基础上,利用超声法对混凝土凝结阶段受扰动后强度变化进行分析,并对桥梁加固混凝土的抗扰动机制进行研究;在此基础上,利用自制调凝型功能外加剂、抗裂增韧外加剂、自愈合功能外加剂提高混凝土的抗扰动性,即缩短混凝土早期受扰影响比较大的时间段(简称受扰期)、减少表面裂缝、提高受扰混凝土自行修补内部微裂纹以恢复强度性能的能力(简称自愈合性);利用正交试验分析3种改善途径的复合效应,研制出不中断交通桥梁加固混凝土功能外加剂的最佳配比:调凝型功能外加剂6%、自愈合功能外加剂9%、抗裂增韧外加剂0.18%(800g/m3)。 展开更多
关键词 桥梁加固混凝土 抗扰动机制 受扰期 表面裂缝 自愈合性
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Hydraulic cylinder control of injection molding machine based on differential evolution fractional order PID 被引量:2
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作者 LI Ya-qiu GU Li-chen +1 位作者 YANG Sha XUE Xu-fei 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2020年第4期317-325,共9页
Injection molding machine,hydraulic elevator,speed actuators belong to variable speed pump control cylinder system.Because variable speed pump control cylinder system is a nonlinear hydraulic system,it has some proble... Injection molding machine,hydraulic elevator,speed actuators belong to variable speed pump control cylinder system.Because variable speed pump control cylinder system is a nonlinear hydraulic system,it has some problems such as response lag and poor steady-state accuracy.To solve these problems,for the hydraulic cylinder of injection molding machine driven by the servo motor,a fractional order proportion-integration-diferentiation(FOPID)control strategy is proposed to realize the speed tracking control.Combined with the adaptive differential evolution algorithm,FOPID control strategy is used to determine the parameters of controller on line based on the test on the servo-motor-driven gear-pump-controlled hydraulic cylinder injection molding machine.Then the slef-adaptive differential evolution fractional order PID controller(SADE-FOPID)model of variable speed pump-controlled hydraulic cylinder is established in the test system with simulated loading.The simulation results show that compared with the classical PID control,the FOPID has better steady-state accuracy and fast response when the control parameters are optimized by the adaptive differential evolution algorithm.Experimental results show that SADE-FOPID control strategy is effective and feasible,and has good anti-load disturbance performance. 展开更多
关键词 variable speed pump-controlled cylinder fractional order proportion-integration-differentiation(FOPID) self-adaptive differential evolution(SADE) injection molding machine control anti-load disturbance
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