主要研究在轴向过载下丁羟推进剂的压强耦合响应,基于双脉冲外部激励的方法,建立了 T 型燃烧器旋转过载试验系统,开展了丁羟推进剂在 0g、5g、15g 轴向载荷下的压强耦合响应试验研究,获得了丁羟推进剂在 T 型燃烧室中的燃面增益常数。...主要研究在轴向过载下丁羟推进剂的压强耦合响应,基于双脉冲外部激励的方法,建立了 T 型燃烧器旋转过载试验系统,开展了丁羟推进剂在 0g、5g、15g 轴向载荷下的压强耦合响应试验研究,获得了丁羟推进剂在 T 型燃烧室中的燃面增益常数。试验结果表明,轴向过载值越大,T 型燃烧器平均工作压强越低,包覆套筒里凝相残渣质量越多,分析认为过载下铝粉在药面过度聚集使得铝粉未充分燃烧,导致丁羟推进剂能量没有充分释放;随着轴向加速度的增加,T 型燃烧器燃面增益常数和凝相粒子浓度减小,从而造成阻尼效果明显减弱。展开更多
In this paper the coefficient and law of the size effect of RPC were studied through experiments and theoretical analysis. The size-effect coefficients for the compressive strength of RPC are deduced through experimen...In this paper the coefficient and law of the size effect of RPC were studied through experiments and theoretical analysis. The size-effect coefficients for the compressive strength of RPC are deduced through experiments.They indicate that RPC without fiber behaves quite the same as normal or high strength concrete.The size effect on compressive strength is more prominent in RPC containing fiber.Bazant's size effect formula of compressive strength applies to RPC.A formula is given to predict the compressive strength of cubic RPC specimens 100 mm on a side where the fiber dosage ranges from 0-2%.展开更多
The effects of adding alloy element zinc on the static and dynamic mechanical properties of copper-zinc alloy were investigated. Tensile and low cycle fatigue behaviors of the C11000 copper and H63 copper-zinc alloy w...The effects of adding alloy element zinc on the static and dynamic mechanical properties of copper-zinc alloy were investigated. Tensile and low cycle fatigue behaviors of the C11000 copper and H63 copper-zinc alloy were obtained by using a miniature tester that combined the functions of in situ tensile and fatigue testing. A piezoelectric actuator was adopted as the actuator for the fatigue testing, and the feasibility of the fatigue actuator was verified by the transient harmonic response analysis based on static tensile preload and dynamic sinusoidal load. The experimental results show that the yield strength and tensile strength of the C11000 copper are improved after adding 37%(mass fraction) zinc, and H63 copper-zinc alloy presents more obvious cyclic hardening behavior and more consumed irreversible plastic work during each stress cycle compared with C11000 copper for the same strain controlled cycling. Additionally, based on the Manson-Coffin theory, the strain-life equations of the two materials were also obtained. C11000 copper and H63 copper-zinc alloy show transition life of 16832 and 1788 cycles, respectively.展开更多
文摘主要研究在轴向过载下丁羟推进剂的压强耦合响应,基于双脉冲外部激励的方法,建立了 T 型燃烧器旋转过载试验系统,开展了丁羟推进剂在 0g、5g、15g 轴向载荷下的压强耦合响应试验研究,获得了丁羟推进剂在 T 型燃烧室中的燃面增益常数。试验结果表明,轴向过载值越大,T 型燃烧器平均工作压强越低,包覆套筒里凝相残渣质量越多,分析认为过载下铝粉在药面过度聚集使得铝粉未充分燃烧,导致丁羟推进剂能量没有充分释放;随着轴向加速度的增加,T 型燃烧器燃面增益常数和凝相粒子浓度减小,从而造成阻尼效果明显减弱。
基金Project 50508005 supported by the National Natural Science Foundations of China
文摘In this paper the coefficient and law of the size effect of RPC were studied through experiments and theoretical analysis. The size-effect coefficients for the compressive strength of RPC are deduced through experiments.They indicate that RPC without fiber behaves quite the same as normal or high strength concrete.The size effect on compressive strength is more prominent in RPC containing fiber.Bazant's size effect formula of compressive strength applies to RPC.A formula is given to predict the compressive strength of cubic RPC specimens 100 mm on a side where the fiber dosage ranges from 0-2%.
基金Projects(51275198,51422503)supported by the National Natural Science Foundation of ChinaProject(2012YQ030075)supported by Special Funds for Development of National Major Scientific Instruments and Equipments,China+1 种基金Project(NECT-12-0238)supported by Program for New Century Excellent Talents in University,ChinaProject(20150520108JH)supported by Young Scientist Fund of Jilin Province of China
文摘The effects of adding alloy element zinc on the static and dynamic mechanical properties of copper-zinc alloy were investigated. Tensile and low cycle fatigue behaviors of the C11000 copper and H63 copper-zinc alloy were obtained by using a miniature tester that combined the functions of in situ tensile and fatigue testing. A piezoelectric actuator was adopted as the actuator for the fatigue testing, and the feasibility of the fatigue actuator was verified by the transient harmonic response analysis based on static tensile preload and dynamic sinusoidal load. The experimental results show that the yield strength and tensile strength of the C11000 copper are improved after adding 37%(mass fraction) zinc, and H63 copper-zinc alloy presents more obvious cyclic hardening behavior and more consumed irreversible plastic work during each stress cycle compared with C11000 copper for the same strain controlled cycling. Additionally, based on the Manson-Coffin theory, the strain-life equations of the two materials were also obtained. C11000 copper and H63 copper-zinc alloy show transition life of 16832 and 1788 cycles, respectively.
