Zr 52 Cu 18 Ni 15 Al 10 Ti 5 bulk glass samples with a diameter of 8 mm prepared by copper mold with water cooling have a mixing structure of amorphous phase and quenched in crystals. By isothermal annealing at differ...Zr 52 Cu 18 Ni 15 Al 10 Ti 5 bulk glass samples with a diameter of 8 mm prepared by copper mold with water cooling have a mixing structure of amorphous phase and quenched in crystals. By isothermal annealing at different temperatures, the crystallization process of the glass alloy is shown to be a multi staged crystallization reaction as follows: Am+quenched in crystals→Am′+cellular phase+(Zr, Ti) Al→Am′+cellular phase+(Zr, Ti) Al+(Zr, Ti) 2(Cu, Ni). Morphology of the quenched in crystals changes from dot or dendritic phase in the as cast bulk glass to cellular phase at different annealing states. The residual region surrounded by the cellular phase has a mixing structure of nano scale phase and amorphous phase.展开更多
以直腿半圆形UCC拱架为对象,进行了不同侧压比荷载条件下的全尺寸拱架试验研究,从变形破坏形态、承载力、材料应变等方面进行对比分析,掌握了新型拱架的承载特性和屈服失稳机制。拱架受力初期处于线弹性变形阶段,拱架内力呈显著压弯状态...以直腿半圆形UCC拱架为对象,进行了不同侧压比荷载条件下的全尺寸拱架试验研究,从变形破坏形态、承载力、材料应变等方面进行对比分析,掌握了新型拱架的承载特性和屈服失稳机制。拱架受力初期处于线弹性变形阶段,拱架内力呈显著压弯状态,由于部分截面出现了强度破坏而导致拱架整体屈服,而后随持续加载拱架出现整体结构失稳,进而彻底丧失承载能力。UCC29试验拱架在λ=1.0加载条件下整体屈服承载力为1 230 k N,是相同尺寸U36拱架的1.56倍。拱架屈服承载力随侧压比λ(λ≥0.5)呈指数型降低趋势,且拱架变形形态及危险截面位置也受侧压比影响显著。对于直腿半圆形拱架而言,侧压比在一定范围内越小,拱架内力越接近轴压状态,拱架能够承担的荷载也越高。展开更多
文摘Zr 52 Cu 18 Ni 15 Al 10 Ti 5 bulk glass samples with a diameter of 8 mm prepared by copper mold with water cooling have a mixing structure of amorphous phase and quenched in crystals. By isothermal annealing at different temperatures, the crystallization process of the glass alloy is shown to be a multi staged crystallization reaction as follows: Am+quenched in crystals→Am′+cellular phase+(Zr, Ti) Al→Am′+cellular phase+(Zr, Ti) Al+(Zr, Ti) 2(Cu, Ni). Morphology of the quenched in crystals changes from dot or dendritic phase in the as cast bulk glass to cellular phase at different annealing states. The residual region surrounded by the cellular phase has a mixing structure of nano scale phase and amorphous phase.
文摘以直腿半圆形UCC拱架为对象,进行了不同侧压比荷载条件下的全尺寸拱架试验研究,从变形破坏形态、承载力、材料应变等方面进行对比分析,掌握了新型拱架的承载特性和屈服失稳机制。拱架受力初期处于线弹性变形阶段,拱架内力呈显著压弯状态,由于部分截面出现了强度破坏而导致拱架整体屈服,而后随持续加载拱架出现整体结构失稳,进而彻底丧失承载能力。UCC29试验拱架在λ=1.0加载条件下整体屈服承载力为1 230 k N,是相同尺寸U36拱架的1.56倍。拱架屈服承载力随侧压比λ(λ≥0.5)呈指数型降低趋势,且拱架变形形态及危险截面位置也受侧压比影响显著。对于直腿半圆形拱架而言,侧压比在一定范围内越小,拱架内力越接近轴压状态,拱架能够承担的荷载也越高。
