检索结果-南通市图书馆

复合材料层合板钝头体高能量低速冲击响应与损伤特性

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

复合材料学报 2024年第6期41卷 3271-3278页

作者：邹君刘佳鑫王计真郭亚周李玲玲冯振宇中国民航大学安全科学与工程学院天津300300 民航航空器适航审定技术重点实验室天津300300 中国飞机强度研究所西安710065

高能量大面积钝物冲击(HEWABI)会导致复合材料飞机结构内部发生严重损伤,但在机身外部几乎目视不可见,从而会对飞机运营安全带来较大的威胁。采用不同形状的刚性冲头和橡胶冲头对层合板进行高能量准静态加载试验,随后建立了基于连续介... 详细信息

高能量大面积钝物冲击(HEWABI)会导致复合材料飞机结构内部发生严重损伤,但在机身外部几乎目视不可见,从而会对飞机运营安全带来较大的威胁。采用不同形状的刚性冲头和橡胶冲头对层合板进行高能量准静态加载试验,随后建立了基于连续介质损伤力学(CDM)的仿真分析模型。结果表明:建立的仿真分析模型可有效预测在刚性和橡胶冲头下的响应和损伤情况。当载荷达到40 kN时,刚性冲头下的层合板会发生严重的分层损伤;而橡胶冲头在加载过程中发生大变形,降低了层合板的局部应力,直至90 kN时仍未对层合板产生任何损伤。层合板损伤情况受刚性冲头形状影响较大,橡胶冲头形状则几乎无影响。

关键词：层合板高能量大面积钝物冲击橡胶冲击冲击响应损伤特性

纤维增强大块非晶的各向异性压缩力学行为原位实验研究

在线全文

学校读者我要写书评

暂无评论

兵工学报 2024年第9期45卷 2982-2992页

作者：李英杰李继承李宁郭亚洲西北工业大学航空学院陕西西安710072 中国工程物理研究院总体工程研究所四川绵阳621999 陕西省冲击动力学及其工程应用重点实验室陕西西安710072

钨纤维增强锆基大块非晶复合材料(WF/Zr-based bulk Metallic Glass matrix composite,WF/Zr-MG)由于其高密度、高强度和高绝热剪切敏感性的特点,在动能侵彻领域应用广泛。为了进一步精确表征在正撞和斜撞等穿甲过程中不同穿甲姿态对复... 详细信息

钨纤维增强锆基大块非晶复合材料(WF/Zr-based bulk Metallic Glass matrix composite,WF/Zr-MG)由于其高密度、高强度和高绝热剪切敏感性的特点,在动能侵彻领域应用广泛。为了进一步精确表征在正撞和斜撞等穿甲过程中不同穿甲姿态对复合材料穿甲性能的影响,搭建准静态和动态显微原位压缩实验平台。通过对0°、10°、25°、45°、65°以及90°共6种不同纤维排列角度下的试样进行原位力学性能实验测试和显微图像分析,研究6种不同纤维排列角度WF/Zr-MG的压缩力学行为,进而得到复合材料失效强度随纤维排列角度的变化情况。根据实验结果划定考虑应变率与纤维排列角度WF/Zr-MG的失效强度包络线。所得结果为材料在不同穿甲姿态和加载速率下提供了一个安全应力状态范围参考,对于穿甲材料的研制具有重要意义。

关键词： WF/Zr-MG复合材料原位实验微观分析破坏机理

A NOVEL APPROACH TO TESTING THE DYNAMIC SHEAR RESPONSE OF Ti-6Al-4V

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2012年第3期25卷 299-311页

作者： yazhou guo Yulong Li School of Aeronautics Northwestern Polytechnical UniversityXi'an 710072China

Modifications were made on the traditional split Hopkinson pressure bar （SHPB） system to conduct dynamic shear tests. The shear response of Ti-6A1-4V was acquired at a shear strain rate of 104 s-1 by using this modified apparatus. The geometry as well as the clamping mode of the double-notch specimen was optimized by commercial FEM software ABAQUS, and the feasibility of the experiment set-up was validated. A shear stress calibration coeff^cient of γT = 1.03 and a shear strain calibration coefficient of γT- = 0.50 were *** have employed high- speed photography to record the deformation process, especially the initiation and propagation of adiabatic shear band （ASB）, during the dynamic shear test. The frames show that the time duration from ASB initiation to its completion is less than 2 μs, from which we can estimate that the propagation speed of ASB within Ti-6A1-4V is more than 1250 m/s under such loading conditions. The temperature rise within ASB is also estimated to be △T2 ≈ 1460 ℃ based on energy balance. Such high temperature has led to softening of the material within the ASBs, and has intensified the shear localization and finally resulted in fracture of the material.

关键词： dynamic shear adiabatic shear band ASB double notch SHPB Ti-6A1-4V

Biaxial tensile behavior of Ti-6Al-4V under proportional loading

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2023年第5期36卷 344-362页

作者： Lin QI yazhou guo Kanghua JIN Huaipu KANG Yulong LI School of Aeronautics Northwestern Polytechnical UniversityXi’an 710072China Shaanxi Key Laboratory of Impact Dynamics and Engineering Applications Northwestern Polytechnical UniversityXi’an 710072China School of Civil Aviation Northwestern Polytechnical UniversitySuzhou 215699China NPU Yangzi River Delta Research Institute Suzhou 215400China

The biaxial tensile behavior of isotropic Ti-6Al-4 V is characterized in this paper.A novel cruciform specimen was designed and optimized to achieve uniform stress and strain distribution within the gauge *** tensile tests were conducted at three different loading ratios by the biaxial testing *** Digital Image Correlation(DIC)technique was applied to determine strain distribution,and a high-speed camera was employed to record the fracture *** Inverse Analysis(IA)approach with a combined experimental and numerical method was proposed to determine the true stresses at the gauge section of the specimen during biaxial tensile *** results indicate that the initial yield locus can be described by the Cazacu criterion accurately,whereas the Mises criterion can predict better the strengthening behavior of Ti-6Al-4 V in the first quadrant in the principal stress space.

关键词： Biaxial tensile testing Inverse analysis Strengthening behavior Ti-6Al-4V Yield locus

Dislocation me diate d dynamic tension-compression asymmetry of a Ni_(2)CoFeV_(0.5)Mo_(0.2) medium entropy alloy

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2023年第28期159卷 204-218页

作者： Ao Meng Xiang Chen yazhou guo Yiping Lu Yonghao Zhao Nano and Heterogeneous Materials Center School of Materials Science and EngineeringNanjing University of Science and TechnologyNanjing 210094China School of Aeronautics Northwestern Polytechnical UniversityXi’an 710072China Key Laboratory of Solidification Control and Digital Preparation Technology(Liaoning Province) School of Materials Science and EngineeringDalian University of TechnologyDalian 116024China

Although tension-compression(T-C)asymmetry in yield strength was rarely documented in coarse-grained face centered cubic(FCC)metals as critical resolved shear stress(CRSS)for dislocation slip differs little between tension and compression,the T-C asymmetry in strength,i.e.,higher strength when loaded in compression than in tension,was reported in some FCC high entropy alloys(HEAs)due to twinning and phase transitions activated at high strain regimes in *** this paper,we demonstrate a reversed and atypical tension-compression asymmetry(tensile strength markedly exceeds compressive strength)in a non-equiatomic FCC Ni_(2)CoFeV_(0.5)Mo_(0.2) medium entropy alloy(MEA)under dynamic loading,wherein dislocation slip governs dynamic deformation without twins or phase *** asymme-try can be primarily interpreted as higher CRSS and more hard slip modes(lower average Schmid factor)activated in grains under dynamic tension than ***,larger strain rate sensitivity in dy-namic tension overwhelmingly contributes to the higher flow stress,thanks to the occurrence of more immobile Lomer-locks,narrower spacing of planar slip bands and higher dislocation *** finding may provide some insights into designing MEAs/HEAs with desired properties under extreme conditions such as blast,impact and crash.

关键词： Medium entropy alloy Dynamic deformation Tension-compression asymmetry Slip trace analysis EBSD and TEM

复合材料加筋板高能量低速冲击损伤特性数值研究

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

复合材料科学与工程 2024年第2期 13-19页

作者：冯振宇李玲玲邹君解江王计真郭亚周中国民航大学安全科学与工程学院天津300300 民航航空器适航审定技术重点实验室天津300300 中国飞机强度研究所西安710065

高能量大面积钝物冲击对复合材料飞机运营安全带来较大的威胁。采用Hashin准则和双线性渐进损伤模型模拟层内损伤,采用Cohesive界面元模拟层间损伤,采用Ogden超弹性材料模型作为橡胶材料本构模型,并进行了模型有效性验证,针对复合材料... 详细信息

高能量大面积钝物冲击对复合材料飞机运营安全带来较大的威胁。采用Hashin准则和双线性渐进损伤模型模拟层内损伤,采用Cohesive界面元模拟层间损伤,采用Ogden超弹性材料模型作为橡胶材料本构模型,并进行了模型有效性验证,针对复合材料加筋板开展了高能量软体、硬体低速冲击下的损伤特性数值研究。分别分析了加筋板不同位置在刚性冲头和橡胶冲头高能量低速冲击下的冲击响应和损伤过程,对比研究了在冲击过程中加筋板变形和损伤模式。结果表明,刚性冲击下接触压力较大,局部变形和损伤更严重。橡胶冲击下橡胶变形起到了一定缓冲和分散压力的作用,但接触力峰值与刚性冲击相比高出约23%。冲击位置位于筋条时在刚性冲击下的损伤最严重,损伤主要位于蒙皮、筋条腹板和缘条,在橡胶冲击下损伤主要位于蒙皮背部和筋条腹板。与刚性冲击相比,不同位置橡胶冲击下的损伤较小且几乎外部目视不可见。

关键词：复合材料加筋板高能量冲击低速冲击橡胶冲击损伤特性

在线全文

学校读者我要写书评

暂无评论

奶牛生产国家在线精品课程建设与实践

草业科学 2024年第09期41卷 2190-2196页

作者：牛华锋谢晓刚白军郭亚洲赵永攀李骁勇杨凌职业技术学院动物工程分院陕西畜牧产业试验示范中心现代牧业(宝鸡)有限公司

奶牛生产课是高等职业教育畜牧兽医专业的核心课程，是一门实践性极强的应用型专业课程。为突出学生实践技能培养、激发学生兴趣，落实立德树人，课程教学内容以产业需求和岗位职业需求为导向，以“精准育人、学训一体、岗位成才”为途... 详细信息

奶牛生产课是高等职业教育畜牧兽医专业的核心课程，是一门实践性极强的应用型专业课程。为突出学生实践技能培养、激发学生兴趣，落实立德树人，课程教学内容以产业需求和岗位职业需求为导向，以“精准育人、学训一体、岗位成才”为途径进行课程改革，有效地将牧场岗位工作任务和教学内容、工作过程、学习过程、岗位评价与学习评价紧密结合，使知识传授、能力培养和素养教育三者融为一体，培养产业发展需要的理论知识扎实、实践技能强、综合素质高的奶牛产业发展需要的应用型高素质技术技能人才，旨在充分发挥学生的主体性和创新能力培养，促进教学质量持续提升。

关键词：奶牛生产精品课程课程思政实践

Multi-scale modeling for prediction of mechanical performance in brazed GH99 thin-walled structure

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第7期37卷 550-563页

作者： yazhou LIU Shengpeng HU Yanyu SONG Wei FU Xiaoguo SONG Ning guo Weimin LONG State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001China Shandong Institute of Shipbuilding Technology Weihai 264209China China Machinery Intelligent Equipment Innovation Research Institute(Ningbo)Co. Ltd.Ningbo 315700China

Superalloy thin-walled structures are achieved mainly by brazing,but the deformation process of brazed joints is non-uniform,making it a challenging research *** paper records a thorough investigation of the effect of brazing parameters on the microstructure of joints and its mechanical properties,which mainly inquires into the deformation and fracture mechanisms in the shearing process of GH99/BNi-5a/GH99 *** macroscopic-microscopic deformation mechanism of the brazing interface during shearing was studied by Crystal Plasticity(CP)and Molecular Dynamics(MD)on the basis of the optimal brazing *** experimental results show that the brazing interface is mainly formed by(Ni,Cr,Co)(s,s)and possesses a shear strength of approximately 546 *** shearing fracture of the brazed joint occurs along the brazing seam,displaying the characteristics of intergranular *** simulations show that dislocations disassociate and transform into fine twinning with increased *** simulated the shear deformation process of the brazed *** multiscale simulation results are consistent with the experimental *** mechanical properties of thin-walled materials for brazing are predicted using MD and CP methods.

关键词： Multi-scale modeling Brazing Shear mechanisms Crystal plasticity GH99 superalloy

在线全文

学校读者我要写书评

暂无评论

航空铆钉的动态力学性能测试

航空学报 2014年第11期35卷 3012-3024页

作者：杨沛郭亚洲李玉龙西北工业大学航空学院陕西西安710072

在飞机鸟撞的课题研究中,数值模拟占据着日益重要的地位,而数值模拟的精度在很大程度上依赖于铆钉力学参数的准确性,但是目前航空铆钉的动态力学性能参数还很匮乏。本文测定了航空铝合金铆钉在不同加载速度下的剪切和拉伸力学性能。设... 详细信息

在飞机鸟撞的课题研究中,数值模拟占据着日益重要的地位,而数值模拟的精度在很大程度上依赖于铆钉力学参数的准确性,但是目前航空铆钉的动态力学性能参数还很匮乏。本文测定了航空铝合金铆钉在不同加载速度下的剪切和拉伸力学性能。设计了基于分离式Hopkinson拉杆系统的铆钉动态性能测试装置,并利用此装置对7种不同型号的航空铆钉进行了动态剪切和拉伸试验,得到了每种型号铆钉的动态力学性能。利用电子万能试验机对7种铆钉进行了两种应变率下的准静态剪切和拉伸试验,并且和动态试验结果进行对比。讨论了加载速度、加载形式、铆钉直径以及铆钉形式对铆钉力学性能的影响,并利用扫描电子显微镜(SEM)观察了铆钉剪切破坏以及拉伸破坏的断口形貌,分析了其破坏形式。本文的研究结果对于航空铝合金铆钉在工程中的应用、尤其是在抗冲击领域的应用具有指导意义。

关键词：分离式霍普金森拉杆电子万能试验机铆钉剪切拉伸扫描电子显微镜