为研究梁拱协作体系相较于传统单一型桥梁结构其抗震性能的优越性,以某三跨梁拱协作体系桥梁为工程背景,利用midas Civil建立该工程桥梁有限元数值分析模型,并建立同尺寸拱桥及简支梁模型,开展对比分析,研究不同工况下的静力特性,为进...为研究梁拱协作体系相较于传统单一型桥梁结构其抗震性能的优越性,以某三跨梁拱协作体系桥梁为工程背景,利用midas Civil建立该工程桥梁有限元数值分析模型,并建立同尺寸拱桥及简支梁模型,开展对比分析,研究不同工况下的静力特性,为进一步研究桥梁结构的动力特性,对结构输入典型的EL Centro Site波,分析桥梁结构在不同方向上的地震动响应,进而开展结构抗震性能分析。结果表明,对比单一型桥梁,在自重情况下,梁拱协作体系比传统梁桥位移响应减少95%,比传统拱桥减少93%,有效减少桥梁结构在静力荷载下的位移响应,其耐久性和安全性更加优秀。在结构模态分析中,梁拱协作体系桥梁频率最大,周期最小,结构刚度与抗扭刚度高于传统单一型桥梁。在同等地震波的作用下,梁拱协作体系桥梁波动区间均处于拱桥与梁桥之间,其结构抗震性能较传统单一型桥梁最强。展开更多
以对叔丁基苯酚为原料,经一步法制得对叔丁基杯[6]芳烃。通过逆傅克反应、亲核取代反应制得二烷基化杯[6]芳烃。最后通过磺化、亲核取代等反应,合成了下缘含喹啉基长链的新型夹状醚杯[6]芳烃化合物( 2a~ 2c ),其结构经 1 H NMR, 13 C NM...以对叔丁基苯酚为原料,经一步法制得对叔丁基杯[6]芳烃。通过逆傅克反应、亲核取代反应制得二烷基化杯[6]芳烃。最后通过磺化、亲核取代等反应,合成了下缘含喹啉基长链的新型夹状醚杯[6]芳烃化合物( 2a~ 2c ),其结构经 1 H NMR, 13 C NMR和HR-MS(ESI-QTOF)表征。以10.0 mol%杯[6]芳烃化合物( 2b )为相转移催化剂,20.0 mol%KOH为催化剂,THF为溶剂,较高产率和高选择性地合成了一系列( Z )-1,2-二芳硒基烯化合物,其结构经 1 H NMR和NOESY确证。 2b 重复使用6次,催化活性无明显降低。展开更多
The effect of T6I6 treatment on the dynamic mechanical and microstructure behaviour of Al-Si-Mg-Cu cast alloy was investigated using split Hopkinson pressure bar(SHPB), transmission electron microscopy(TEM), and highr...The effect of T6I6 treatment on the dynamic mechanical and microstructure behaviour of Al-Si-Mg-Cu cast alloy was investigated using split Hopkinson pressure bar(SHPB), transmission electron microscopy(TEM), and highresolution transmission electron microscopy(HRTEM). Besides, the impact resistances of T6I6 and T6 motor shells of new energy vehicles made of Al-Si-Mg-Cu cast alloy were compared using a trolley crash test. The results indicated that the main strengthening-phases of the T6 peak-aged and T6I6 peak-aged alloy were GP zone and β″ precipitates. T6I6treatment can increase the density and size of β″ precipitates in peak-aged alloy and enhance both its tensile strength(σb)and elongation(δ). The dynamic toughness values of T6I6 samples are 50.34 MJ/m^(3) at 2000 s^(-1) and 177.34 MJ/m^(3) at 5000 s^(-1) which are 20% and 12% higher than those of T6 samples, respectively. Compared with a T6 shell, the overall deformation of T6I6 shell is more uniform during the crash test. At an impact momentum of 3.5×10;kg·m/s, the T6I6shell breaks down at 0.38 s which is 0.10 s later than the T6 shell.展开更多
文摘为研究梁拱协作体系相较于传统单一型桥梁结构其抗震性能的优越性,以某三跨梁拱协作体系桥梁为工程背景,利用midas Civil建立该工程桥梁有限元数值分析模型,并建立同尺寸拱桥及简支梁模型,开展对比分析,研究不同工况下的静力特性,为进一步研究桥梁结构的动力特性,对结构输入典型的EL Centro Site波,分析桥梁结构在不同方向上的地震动响应,进而开展结构抗震性能分析。结果表明,对比单一型桥梁,在自重情况下,梁拱协作体系比传统梁桥位移响应减少95%,比传统拱桥减少93%,有效减少桥梁结构在静力荷载下的位移响应,其耐久性和安全性更加优秀。在结构模态分析中,梁拱协作体系桥梁频率最大,周期最小,结构刚度与抗扭刚度高于传统单一型桥梁。在同等地震波的作用下,梁拱协作体系桥梁波动区间均处于拱桥与梁桥之间,其结构抗震性能较传统单一型桥梁最强。
基金Projects(52075166, 51875197) supported by the National Natural Science Foundation of ChinaProjects(2019RS2064,2019GK5043) supported by the Science and Technology Planning Project of Hunan Province,China。
文摘The effect of T6I6 treatment on the dynamic mechanical and microstructure behaviour of Al-Si-Mg-Cu cast alloy was investigated using split Hopkinson pressure bar(SHPB), transmission electron microscopy(TEM), and highresolution transmission electron microscopy(HRTEM). Besides, the impact resistances of T6I6 and T6 motor shells of new energy vehicles made of Al-Si-Mg-Cu cast alloy were compared using a trolley crash test. The results indicated that the main strengthening-phases of the T6 peak-aged and T6I6 peak-aged alloy were GP zone and β″ precipitates. T6I6treatment can increase the density and size of β″ precipitates in peak-aged alloy and enhance both its tensile strength(σb)and elongation(δ). The dynamic toughness values of T6I6 samples are 50.34 MJ/m^(3) at 2000 s^(-1) and 177.34 MJ/m^(3) at 5000 s^(-1) which are 20% and 12% higher than those of T6 samples, respectively. Compared with a T6 shell, the overall deformation of T6I6 shell is more uniform during the crash test. At an impact momentum of 3.5×10;kg·m/s, the T6I6shell breaks down at 0.38 s which is 0.10 s later than the T6 shell.
