采用三维编织技术和真空辅助树脂灌注成型工艺制备了碳/玻混杂三维五向编织复合材料工字梁,对不同混杂比例和不同混杂部位的复合材料工字梁进行四点弯曲测试,结合三维数字图像相关(3D Digital Image Correlation,3D-DIC)技术分析其应变...采用三维编织技术和真空辅助树脂灌注成型工艺制备了碳/玻混杂三维五向编织复合材料工字梁,对不同混杂比例和不同混杂部位的复合材料工字梁进行四点弯曲测试,结合三维数字图像相关(3D Digital Image Correlation,3D-DIC)技术分析其应变分布和损伤过程。结果表明:采用不同混杂比例时,1/3碳纤维轴纱和2/3碳纤维轴纱相比纯玻璃纤维试样的强度提升了4.5%和11.5%,随着碳纤维占比的增加,复合材料的强度逐渐提升,但提升幅度较小;而碳纤维分布位置不同时,工字梁弯曲失效形式也不同,纯玻璃纤维和碳纤维在下翼缘的2种试样属于下压头附近边缘断裂的失效形式,碳纤维在腹板、腹板和下翼缘的2种试样属于腹板前后错位倾斜的失效形式,碳纤维在上翼缘、上翼缘和下翼缘、上翼缘和腹板的3种试样都属于腹板中心纵向断裂的失效形式;结合位移-载荷曲线及失效形式分析可知,1/3碳纤维分布于上翼缘,2/3碳纤维分布于上翼缘和下翼缘时,工字梁强度及抵抗变形的能力更佳,碳纤维更适合混杂于上翼缘。展开更多
The dynamic mechanical relaxation behavior of Ti36.2Zr30.3Cu8.3Fe4Be21.2 bulk metallic glass with good glass-forming ability was investigated by mechanical spectroscopy.The mechanical relaxation behavior was analyzed ...The dynamic mechanical relaxation behavior of Ti36.2Zr30.3Cu8.3Fe4Be21.2 bulk metallic glass with good glass-forming ability was investigated by mechanical spectroscopy.The mechanical relaxation behavior was analyzed in the framework of quasi-point defects model.The experimental results demonstrate that the atomic mobility of the metallic glass is closely associated with the correlation factorχ.The physical aging below the glass transition temperature T g shows a non-Debye relaxation behavior,which could be well described by stretched Kohlrausch exponential equation.The Kohlrausch exponentβaging reflects the dynamic heterogeneities of the metallic glass.Both concentration of"defects"and atomic mobility decrease caused by the in situ successive heating during the mechanical spectroscopy experiments.展开更多
Shaking table tests and theoretical analysis were conducted to study the dynamic performance of cable net facade with consideration of glass panels under earthquake. Firstly,the dynamic response of cable net faade u...Shaking table tests and theoretical analysis were conducted to study the dynamic performance of cable net facade with consideration of glass panels under earthquake. Firstly,the dynamic response of cable net faade under earthquake was investigated with shaking table test. Then the working mechanism of glass panels in coordination with cable net was proposed. Accordingly,a numerical simulation model of glass panel's working in coordination with cable net was built for the dynamic analysis.And then the seismic response was analyzed with this model theoretically. The study indicates that the seismic response of the cable net with glass panels on most occasions is mainly decided by the symmetric modes,and the first vibration mode is dominant. The damping of cable net facade is mainly decided by glass panels. And it is very good for cable net faade to restrain its dynamic response under earthquake.展开更多
In order to remove hydrogen and inclusions from A356 alloy melt, a low melting point glass flux, JDN Ⅱ, was developed. The results indicated that JDN Ⅱ flux has distinct effect of purification and protection on A356...In order to remove hydrogen and inclusions from A356 alloy melt, a low melting point glass flux, JDN Ⅱ, was developed. The results indicated that JDN Ⅱ flux has distinct effect of purification and protection on A356 alloy melt. When the dosage of the flux was 3%, the content of hydrogen in A356 melt was only 2.6?mL/kg at 857?℃ and 0.7?mL/kg even at 750?℃. In the meantime, the mechanical properties of the alloy increase greatly with the covering of 3% JDN Ⅱ flux. Compared with no flux, the tensile strength of A356 alloy increases by 9.42% and the elongation increases by 22%. The purification mechanism of JDN Ⅱ glass flux was discussed too.展开更多
High entropy bulk metallic glasses show promising mechanical and physical properties.Dynamic mechanical properties of Ti_（16.7）Zr_（16.7）Hf_（16.7）Cu_（16.7）Ni_（16.7）Be_（16.7）high entropy bulk metallic glass ...High entropy bulk metallic glasses show promising mechanical and physical properties.Dynamic mechanical properties of Ti_（16.7）Zr_（16.7）Hf_（16.7）Cu_（16.7）Ni_（16.7）Be_（16.7）high entropy bulk metallic glass were investigated by mechanical spectroscopy（or called dynamic mechanical analysis）.The main（α）relaxation was observed in the framework of the loss modulus G″,which is related to the dynamic glass transition behaviour for the glassy materials.From physical model point of view,dynamic mechanical properties of the Ti_（16.7）Zr_（16.7）Hf_（16.7）Cu_（16.7）Ni_（16.7）Be_（16.7）high entropy bulk metallic glass show good agreement compared with the quasi-point defects theory.展开更多
文摘采用三维编织技术和真空辅助树脂灌注成型工艺制备了碳/玻混杂三维五向编织复合材料工字梁,对不同混杂比例和不同混杂部位的复合材料工字梁进行四点弯曲测试,结合三维数字图像相关(3D Digital Image Correlation,3D-DIC)技术分析其应变分布和损伤过程。结果表明:采用不同混杂比例时,1/3碳纤维轴纱和2/3碳纤维轴纱相比纯玻璃纤维试样的强度提升了4.5%和11.5%,随着碳纤维占比的增加,复合材料的强度逐渐提升,但提升幅度较小;而碳纤维分布位置不同时,工字梁弯曲失效形式也不同,纯玻璃纤维和碳纤维在下翼缘的2种试样属于下压头附近边缘断裂的失效形式,碳纤维在腹板、腹板和下翼缘的2种试样属于腹板前后错位倾斜的失效形式,碳纤维在上翼缘、上翼缘和下翼缘、上翼缘和腹板的3种试样都属于腹板中心纵向断裂的失效形式;结合位移-载荷曲线及失效形式分析可知,1/3碳纤维分布于上翼缘,2/3碳纤维分布于上翼缘和下翼缘时,工字梁强度及抵抗变形的能力更佳,碳纤维更适合混杂于上翼缘。
基金supported by the National Natural Science Foundation of China (Nos. 51611130120, 11772257, 11572249, 51871132)supported by the Fundamental Research Funds for the Central Universities (Nos. 3102018ZY010, 3102017HQZZ012)
文摘The dynamic mechanical relaxation behavior of Ti36.2Zr30.3Cu8.3Fe4Be21.2 bulk metallic glass with good glass-forming ability was investigated by mechanical spectroscopy.The mechanical relaxation behavior was analyzed in the framework of quasi-point defects model.The experimental results demonstrate that the atomic mobility of the metallic glass is closely associated with the correlation factorχ.The physical aging below the glass transition temperature T g shows a non-Debye relaxation behavior,which could be well described by stretched Kohlrausch exponential equation.The Kohlrausch exponentβaging reflects the dynamic heterogeneities of the metallic glass.Both concentration of"defects"and atomic mobility decrease caused by the in situ successive heating during the mechanical spectroscopy experiments.
基金Sponsored by National "Eleventh Five-Year" Technological Supporting Plan (Grant No.2006BAJ02A05)National Natural Science Foundation of China(Grant No.50908044)+1 种基金China Postdoctoral Foundation (Grant No.20070420164)Shenzhen Technical Foundation (Grant No.20080624_1554)
文摘Shaking table tests and theoretical analysis were conducted to study the dynamic performance of cable net facade with consideration of glass panels under earthquake. Firstly,the dynamic response of cable net faade under earthquake was investigated with shaking table test. Then the working mechanism of glass panels in coordination with cable net was proposed. Accordingly,a numerical simulation model of glass panel's working in coordination with cable net was built for the dynamic analysis.And then the seismic response was analyzed with this model theoretically. The study indicates that the seismic response of the cable net with glass panels on most occasions is mainly decided by the symmetric modes,and the first vibration mode is dominant. The damping of cable net facade is mainly decided by glass panels. And it is very good for cable net faade to restrain its dynamic response under earthquake.
文摘In order to remove hydrogen and inclusions from A356 alloy melt, a low melting point glass flux, JDN Ⅱ, was developed. The results indicated that JDN Ⅱ flux has distinct effect of purification and protection on A356 alloy melt. When the dosage of the flux was 3%, the content of hydrogen in A356 melt was only 2.6?mL/kg at 857?℃ and 0.7?mL/kg even at 750?℃. In the meantime, the mechanical properties of the alloy increase greatly with the covering of 3% JDN Ⅱ flux. Compared with no flux, the tensile strength of A356 alloy increases by 9.42% and the elongation increases by 22%. The purification mechanism of JDN Ⅱ glass flux was discussed too.
基金Item Sponsored by National Natural Science Foundation of China(51401192,51301136)Fundamental Research Funds for the Central Universities of China(3102015ZY027,3102015BJ(Ⅱ)JGZ019)+2 种基金Aerospace Technology Foundation of China(N2014KC0068,2015ZF53072)Space Technology Foundation of China(N2014KC0073)Project of State Key Laboratory of Materials Processing and Die & Mould Technology,Huazhong University of Science and Technology(P2016-12)
文摘High entropy bulk metallic glasses show promising mechanical and physical properties.Dynamic mechanical properties of Ti_（16.7）Zr_（16.7）Hf_（16.7）Cu_（16.7）Ni_（16.7）Be_（16.7）high entropy bulk metallic glass were investigated by mechanical spectroscopy（or called dynamic mechanical analysis）.The main（α）relaxation was observed in the framework of the loss modulus G″,which is related to the dynamic glass transition behaviour for the glassy materials.From physical model point of view,dynamic mechanical properties of the Ti_（16.7）Zr_（16.7）Hf_（16.7）Cu_（16.7）Ni_（16.7）Be_（16.7）high entropy bulk metallic glass show good agreement compared with the quasi-point defects theory.
