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知识与数据交互驱动的力学性能极限研究进展 被引量:1
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作者 高恩来 《固体力学学报》 CAS CSCD 北大核心 2024年第2期170-187,共18页
探索物质力学性能极限是科学研究的前沿,发掘极限力学性能物质(材料或结构)可为国防军工等尖端领域发展提供物资基础.然而,杨氏模量、抗拉强度等力学性能的理论极限未知,引发长期以来悬而未决的争议与迷茫,诸如是否存在比金刚石更刚、... 探索物质力学性能极限是科学研究的前沿,发掘极限力学性能物质(材料或结构)可为国防军工等尖端领域发展提供物资基础.然而,杨氏模量、抗拉强度等力学性能的理论极限未知,引发长期以来悬而未决的争议与迷茫,诸如是否存在比金刚石更刚、更硬的物质?人类是否已经接近材料力学性能的边界?化学元素相互组合可形成无穷物质,仅已知物质结构就多达数百万种且数目仍在快速增长,从中发掘出性能突破现有纪录的物质挑战巨大.知识与数据交互驱动的研究范式源远流长、历久弥新,是发展和革新力学理论的宝典.近年来,在新型知识与数据交互驱动下,研究人员发展了更高效能的物质性能预报理论,确定了若干力学性能的理论极限,设计制备出若干性能接近于理论极限的物质.本文回顾梳理了相关领域的研究现状,探讨了相关领域的发展趋势及其面临的机遇与挑战. 展开更多
关键词 知识驱动 数据驱动 结构-性能关联 力学性能极限 极限性能物质
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含能粘弹体的动态力学性能与极限力学性能的关系研究 被引量:2
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作者 范夕萍 刘子如 +1 位作者 孙莉霞 白锦芳 《盐湖研究》 CSCD 2003年第2期56-59,共4页
对动态力学性能与极限力学性能 (抗拉或抗压性能 )之间的关系进行了推导 ,提出了利用它们之间的关系由动态参量来预估极限力学性能的关系式 ,并以MC 1为例 ,证明了储能模量E’与抗压强度σb 之间的关系。
关键词 动态力学性能 极限力学性能 材料力学 粘弹性材料 DMA 动态热机械分析 MC—1推进剂
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RDX基浇铸PBX的老化性能 被引量:9
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作者 丁黎 郑朝民 +2 位作者 梁忆 刘文亮 常海 《含能材料》 EI CAS CSCD 北大核心 2015年第2期156-162,共7页
采用-55-71℃温度循环老化试验,研究了RDX基浇铸高聚物粘结炸药(PBX)老化时,随时间的外观变化、结构完整性、质量/体积变化率、机械感度、力学性能及发射安全性。进行了65,75,85,95℃老化试验和老化样扫描电镜(SEM)及动态力学分析(... 采用-55-71℃温度循环老化试验,研究了RDX基浇铸高聚物粘结炸药(PBX)老化时,随时间的外观变化、结构完整性、质量/体积变化率、机械感度、力学性能及发射安全性。进行了65,75,85,95℃老化试验和老化样扫描电镜(SEM)及动态力学分析(DMA)的研究。结果表明,25个温度循环后,PBX炸药装药内部无可见裂纹和气孔,结构完整性未发生变化,质量/体积变化率小于1%,撞击感度增加到16%,在锤重400 kg和落高3 m的撞击条件下,未发生爆炸,PBX的抗压强度增加、压缩率下降,力学性能显著劣化。65℃恒温老化252 d后,抗压强度增加47.5%,压缩率下降9.8%。随老化时间延长,β松弛的动态力学损耗峰值(tanδ)降低,网络交联程度提高,与填料之间的结合更为紧密,显示后固化交联反应是力学性能劣化的原因之一。 展开更多
关键词 浇铸PBX 加速老化 极限力学性能 动态力学性能
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浇铸改性双基推进剂极限力学性能研究 被引量:3
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作者 刘晓军 谢五喜 +2 位作者 蔚红建 李吉祯 付小龙 《战术导弹技术》 2013年第3期55-58,共4页
研究了不同拉伸速率(20 mm/min、100 mm/min、200 mm/min)、不同测试温度(-50℃、-40℃、-30℃、-20℃、0℃、20℃、50℃)对改性双基推进剂极限抗拉强度σm和极限应变εm的影响,并获得了其相应主曲线。结果表明,随着温度升高,推进剂极... 研究了不同拉伸速率(20 mm/min、100 mm/min、200 mm/min)、不同测试温度(-50℃、-40℃、-30℃、-20℃、0℃、20℃、50℃)对改性双基推进剂极限抗拉强度σm和极限应变εm的影响,并获得了其相应主曲线。结果表明,随着温度升高,推进剂极限抗拉强度σm减小,极限应变εm增大;相同温度时,随着拉伸速率的增大,推进剂的极限抗拉强度σm提高。主曲线的描绘为该类推进剂的力学性能研究提供了有力的分析方法。 展开更多
关键词 改性双基推进剂 极限力学性能 极限抗拉强度 极限应变
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Effect of consolidation parameters on mechanical properties of Cu-based bulk amorphous alloy consolidated by hot pressing 被引量:1
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作者 蔡安辉 熊翔 +5 位作者 刘咏 安伟科 周果君 罗云 李铁林 李小松 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第8期2032-2040,共9页
Cu50Zr40Ti10 bulk amorphous alloys were fabricated by hot pressing gas-atomized Cu50Zr40Ti10 amorphous powder under different consolidation conditions without vacuum and inert gas protection. The consolidation conditi... Cu50Zr40Ti10 bulk amorphous alloys were fabricated by hot pressing gas-atomized Cu50Zr40Ti10 amorphous powder under different consolidation conditions without vacuum and inert gas protection. The consolidation conditions of the Cu50Zr40Ti10 amorphous powder were investigated based on an L9(34) orthogonal design. The compression strength and strain limit of the Cu50Zr40Ti10 bulk amorphous alloys can reach up to 1090.4 MPa and 11.9 %, respectively. The consolidation pressure significantly influences the strain limit and compression strength of the compact. But the mechanical properties are not significantly influenced by the consolidation temperature. In addition, the preforming pressure significantly influences not the compression strength but the strain limit. The optimum consolidation condition for the Cu50Zr40Ti10 amorphous powder is first precompacted under the pressure of 150 MPa, and then consolidated under the pressure of 450 MPa and the temperature of 380 °C. 展开更多
关键词 hot pressing Cu-based amorphous alloy strain limit CONSOLIDATION mechanical property
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Experimental research on mechanical properties of prestressed truss concrete composite beam encased with circular steel tube 被引量:3
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作者 张博一 郑文忠 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2009年第3期338-345,共8页
Tests of 4 simply supported unbonded prestressed truss concrete composite beams encased with circular steel tube were carried out. It is found that the ratio of the stress increment of the unbonded tendon to that of t... Tests of 4 simply supported unbonded prestressed truss concrete composite beams encased with circular steel tube were carried out. It is found that the ratio of the stress increment of the unbonded tendon to that of the tensile steel tube is 0.252 during the using stage,and the average crack space of beams depends on the ratio of the sum of the bottom chord steel tube's outside diameter and the secondary bottom chord steel tube's section area to the effective tensile concrete area. The coefficient of uneven crack distribution is 1.68 and the formula for the calculation of crack width is established. Test results indicate that the ultimate stress increment of unbonded tendon in the beams decreases in linearity with the increase of the composite reinforcement index β0. The pure bending region of beams accords with the plane section assumption from loading to failure. The calculation formula of ultimate stress increment of the unbonded tendon and the method to calculate the bearing capacity of normal section of beams have been presented. Besides,the method to calculate the stiffness of this sort of beams is brought forward as well. 展开更多
关键词 truss concrete composite beam encased with circular steel tube bearing capacity of normal section STIFFNESS crack width unbonded prestressed tendon
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Effect of tempering temperature on microstructure and mechanical properties of AISI 6150 steel 被引量:6
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作者 李红英 胡继东 +2 位作者 李俊 陈广 苏雄杰 《Journal of Central South University》 SCIE EI CAS 2013年第4期866-870,共5页
Effect of tempering temperature on the microstructure and mechanical properties of AISI 6150 steel was investigated. All samples were austenitized at 870 ℃ for 45 min followed by oil quenching, and then tempered at t... Effect of tempering temperature on the microstructure and mechanical properties of AISI 6150 steel was investigated. All samples were austenitized at 870 ℃ for 45 min followed by oil quenching, and then tempered at temperatures between 200 and 600 ℃ for 60 min. The results show that the microstructure of tempered sample at 200 ℃ mainly consists of tempered martensite. With increasing the tempered temperature, the martensite transforms to the ferrite and carbides. The ultimate tensile strength, the hardness and the retained austenite decrease with increasing tempered temperature, and 0.2% yield strength increases when the temperature increases from 200 to 300 ℃ and then decreases with increasing the temperature, but the elongation and impact energy increase with increasing the tempering temperature. 展开更多
关键词 tempering temperature AISI 6150 steel MICROSTRUCTURE mechanical property
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Lateral aerodynamic performance and speed limits of double-deck container vehicles with different structures 被引量:2
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作者 李燕飞 田红旗 《Journal of Central South University》 SCIE EI CAS 2012年第7期2061-2066,共6页
Based on 3D, steady N-S equations and k-e turbulence model, Fluent was employed to do numerical simulation for lateral aerodynamic performance of 6-axis X2K double-deck container trains with two different loading form... Based on 3D, steady N-S equations and k-e turbulence model, Fluent was employed to do numerical simulation for lateral aerodynamic performance of 6-axis X2K double-deck container trains with two different loading forms, and speed limits of the freight trains were studied. The result indicates that under wind environment: 1) As for vehicles without and with cross-loaded structure, aero-pressure on the former is bigger, but air velocity around the latter is larger; 2) When sideslip angle θ=0°, the airflow is symmetry about train vertical axis; when θ〉0°, the airflow is detached at the top of vehicles, and the air velocity increases above the separated line but decreases below it; 3) With θ increasing, the lateral force on the mid vehicle firstly increases but decreases as θ=75°; 4) When the 6-axis X2K fiat car loads empty boxes of a 40 ft and a 48 ft at 120 km/h, the overturning wind speed is 25.19 m/s, and the train should be stopped under the 12th grade wind speed. 展开更多
关键词 numerical simulation 6-axis X2K flat car loading form lateral aerodynamic performance speed limit
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Mechanical and ballistic properties of powder metal 7039 aluminium alloy joined by friction stir welding 被引量:1
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作者 Mehmet ERDEM Hanifi CINICI +2 位作者 Ugur GOKMEN Halil KARAKOC Mehmet TURKER 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2016年第1期74-84,共11页
7039 Al alloy plates which were used as armor materials were produced by powder metallurgy method. The prepared mixed powders were pressed and plated by extrusion process. These plates, after being subjected to T6 hea... 7039 Al alloy plates which were used as armor materials were produced by powder metallurgy method. The prepared mixed powders were pressed and plated by extrusion process. These plates, after being subjected to T6 heat treatment, were joined double-sided by friction stir welding method. Microstructure and microhardness of the welded plate were investigated. It was determined that the finest grain structure and the lowest hardness value occurred in the stir zone as 2-6 mm and HV 80.9, respectively. In order to determine the ballistic properties of welded plates, 7.62 mm armor piercing projectiles were shot to the base metal(BM), heat affected zone(HAZ), and thermomechanically affected zone+stir zone(TMAZ+SZ). Ballistic limits(v_(50)) of these zones were determined. The ballistic limits of the BM, TMAZ+SZ, and HAZ of the plate were approximately 14.7%, 15.3%, and 17.9% lower than that of the standard plate at the same thickness, respectively. It was determined that the armor piercing projectiles created petaling and ductile hole enlargement failure types at the armor plate. Ballistic and mechanical results can be enhanced by hot-cold rolling mills after extrusion and particle reinforcement. 展开更多
关键词 powder metal 7039 Al alloy ballistic limit microstructure mechanical properties
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Effects of Y on mechanical properties and damping capacity of ZK60 magnesium alloys 被引量:2
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作者 王敬丰 高珊 +3 位作者 赵亮 梁浩 胡耀波 潘复生 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2010年第B07期366-370,共5页
The microstructure,mechanical properties and damping capacity of ZK60-xY(x=0,1.5%,2.5%,4.0%,mass fraction) magnesium alloys were investigated by using the optical microscope(OM),X-ray diffractometer(XRD),universal ten... The microstructure,mechanical properties and damping capacity of ZK60-xY(x=0,1.5%,2.5%,4.0%,mass fraction) magnesium alloys were investigated by using the optical microscope(OM),X-ray diffractometer(XRD),universal tensile testing machine and dynamic mechanical analyzer(DMA).The mechanisms for damping capacity of referred alloys were discussed by Granato-Lücke theory.The results show that Y additions remarkably reduce grain size(the average grain size is 21.6,13.0,8.6 and 4.0μm,respectively),and the tensile properties are enhanced with grain refining(the yield tensile strength increases to 292 MPa from 210 MPa and ultimate tensile strength increases to 330 MPa from 315 MPa).For the ZK60-xY(x=0,1.5%,4.0%)alloys,the damping capacity decreases with the increase of Y content.However,for the ZK60-xY(x=2.5%)alloy,the damping capacity improves abnormally,which is possibly related to the formation of Mg3Y2Zn3(W)FCC phase in this alloy. 展开更多
关键词 magnesium alloys MICROSTRUCTURE mechanical property damping capacity Granato-Lücke Theory
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On the Redistribution of Bending Moments in Two-Span RC Beams and Slabs Exposed to Fire
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作者 Robert Kowalski Marek Urbafiski 《Journal of Civil Engineering and Architecture》 2013年第2期158-173,共16页
This paper shows consideration of decrease in cross-section stiffness in commonly used in practice RC (reinforced concrete) beams and slabs in cases when only reinforcing bars or only concrete compressed zone, which... This paper shows consideration of decrease in cross-section stiffness in commonly used in practice RC (reinforced concrete) beams and slabs in cases when only reinforcing bars or only concrete compressed zone, which is subjected to fire. Analyses were based on: (1) standard fire curve [EN 1991-1-2]; (2) 500℃isotherm method assumptions [EN 1992-1-2]; (3) mechanical properties of reinforcing steel heated up to high temperature. Afterwards, based on estimated decrease of cross-sections stiffness, the redistribution of bending moments was calculated in some cases of two-span RC beams and slabs subjected to fire from their bottom face. Due to the bending moment redistribution, one could expect a reduction of bending moments in span cross-sections and an increase of support bending moment. As a result of this phenomenon, the ultimate limit state of the structural multi span elements might occur after shorter fire duration than it could be expected when redistribution of bending moments is neglected. 展开更多
关键词 Concrete CROSS-SECTION fire design stiffness.
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办公楼的钟乳石奇观
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作者 孙尉翔 《新知客》 2010年第3期114-114,共1页
现在的楼房设计,各层的下水道布置是统一的。在走廊的下水口朝上看,就能看见上一层楼的下水道水管。现在用的水管都是那种白色的PVC塑料管了。我们办公楼走廊的每个下水口旁边都有一坨水泥样的东西,抬头看去,上一层楼的水管正吊着一条... 现在的楼房设计,各层的下水道布置是统一的。在走廊的下水口朝上看,就能看见上一层楼的下水道水管。现在用的水管都是那种白色的PVC塑料管了。我们办公楼走廊的每个下水口旁边都有一坨水泥样的东西,抬头看去,上一层楼的水管正吊着一条白白的"钟乳石",正对着地上那坨" 展开更多
关键词 一层楼 硅粉 塑料树脂 极限力学性能 堆石 螺杆机
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Defects production and mechanical properties of typical metal engineering materials under neutron irradiation
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作者 LIU Jian TANG XiaoBin +3 位作者 CHEN FeiDa HUANG Hai LI Huan YANG YaHui 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2015年第10期1753-1759,共7页
Maintaining the safety and reliability of nuclear engineering materials under a neutron irradiation environment is significant. Atomic-scale simulations are conducted to investigate the mechanism of irradiation-induce... Maintaining the safety and reliability of nuclear engineering materials under a neutron irradiation environment is significant. Atomic-scale simulations are conducted to investigate the mechanism of irradiation-induced vacancy formation in CLAM, F82 H and α-Fe with different neutron energies and objective laws of the effect of vacancy concentration on mechanical properties of α-Fe. Damage of these typical metal engineering materials caused by neutrons is mainly displacement damage, while the displacement damage rate and the non-ionizing effect of neutrons decrease with the increase of neutron energy. The elastic modulus, yield strength, and ultimate strength of α-Fe are in the order of magnitude of GPa. However, the elastic modulus is not constant but decreases with the increase of strain at the elastic deformation stage. The ultimate strength reaches its maximum value when vacancy concentration in α-Fe is 0.2%. On this basis, decreasing or increasing the number of vacancies reduces the ultimate strength. 展开更多
关键词 Monte Carlo molecular dynamics neutron irradiation displacement damage rate mechanical properties
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