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Acta Mechanica Solida Sinica 2014年第4期27卷 373-382页

作者： Quanwei Zhan Tao Suo Cunxian Wang Kui Xie zhongbin tang Institute of UAV research Northwestern Polytechnical University School of Aeronautics Northwestern Polytechnical University Department of Mechanical Engineering The Johns Hopkins University 3400 N. Charles StreetBaltimore MD 21218 USA China Electronics Technology Group Corporation No.38 Research Institute

In the present work, we explore the strain hardening behaviors as well as the effect of temperature on the plastic deformation of ultrafine grained aluminum. The temperature sensitivity is determined and compared with that of coarse grained material. The results indicate that the flow stress of ultrafine grained aluminum displays enhanced sensitivity to temperature. The reduction in activation volume is suggested to be the major reason for the enhanced temperature sensitivity as grain size is refined into the sub-micrometer regime. Finally, a phenomenological constitutive model is proposed to describe the post-yield response of ultrafine grained aluminum.

关键词： ultrafine grained aluminum compressive behavior temperature sensitivity strain hardening behavior constitutive relation

High-velocity impact responses of 2618 aluminum plates for engine containment systems under combined actions of projectile form and oblique angle

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Chinese Journal of Aeronautics 2019年第6期32卷 1428-1441页

作者： Cunxian WANG Tao SUO Yulong LI Pu XUE zhongbin tang School of Aeronautics Northwestern Polytechnical UniversityXi’an 710072China Shaanxi Key Laboratory of Impact Dynamics and Engineering Application(IDEA) Northwestern Polytechnical UniversityXi’an 710072China Fundamental Science on Aircraft Structural Mechanics and Strength Laboratory Northwestern Polytechnical UniversityXi’an 710072China

Ballistic impact tests were carried out with examined projectiles of the Ti-6Al-4V titanium alloy to investigate the impact response of the 2618 aluminum plates at a nominal velocity of 210 m/s. The influence of projectile forms and oblique angles on damage formation was particularly discussed by applying different loading conditions such as multiple projectile forms and oblique angles. Additionally, the numerical simulation method was employed to provide further insight into the characteristics of damage and target responses. The Johnson-Cook(J-C)constitutive model with revised failure parameters was used to support the simulations to assess target responses and characteristics of the damage created from different impact conditions. Results show that there is a significant transition in the deformation mode as changes of the projectile form are applied. Moreover, the cracks on the back of the 2618 aluminum alloy plates impacted by the solid plate projectile and the hollow blade projectile tend to locate at different positions, which are supposed to be influenced by local bending and stretching. The work in this paper may provide guidance for the design of fan blade containment systems.

关键词： 2618 aluminum plate Damage characteristic High-velocity impact Johnson-Cook(J-C) Projectile forms

Effects of surface topography and specimen thickness on high-speed raindrop impact damage of CFRP laminates

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Chinese Journal of Aeronautics 2023年第6期36卷 186-200页

作者： Naidan HOU Renxi ZHAO Xuan WANG zhongbin tang Hao CUI Yulong LI School of Aeronautics Northwestern Polytechnical UniversityXi'an 710072China Joint International Research Laboratory of Impact Dynamics and Engineering Application Xi'an 710072China Shaanxi Key Laboratory of Impact Dynamics and Engineering Application Xi'an 710072China School of Civil Aviation Northwestern Polytechnical UniversitySuzhou 215400China NPU Yangzi River Delta Research Institute Suzhou 215400China

Raindrop impact erosion has been observed since early days of aviation,and can be catastrophic for exposed materials during supersonic flight.A single impact waterjet apparatus is established for mimicking drop impacts at the velocities between 350 m/s and 620 m/*** Fiber Reinforced Polymer(CFRP)laminates with three different surface morphologies and specimen thicknesses are tested here.A central region with no visible damage has been noticed,surrounded by a"failure ring"with common damage patterns including resin removal,matrix cracking,fiber breakage and mass fiber *** features are presented in the"failure ring"whose whole scope extends larger along the longitudinal direction than the transverse direction of the top *** mechanism of the resin removal is related to fiber-matrix debonding,and its onset and propagation can be facilitated by initial surface asperities with the shear action of the lateral *** cases of multiple impact,good surface quality can slow down the evolution of resin removal and fiber exposure on the CFRP surface,reducing the erosion speed and delaying the occurrence of structural damages in the subsequent *** wave dominates the occurrence of matrix cracking on the CFRP surface,and subsequently,results in material loss and peeling of the top-layer because of lateral *** the increase of the specimen thickness,both the interlaminar and intralaminar failures decrease as the impact damage mechanism changes from plate bending stress to the reflection of stress waves.

关键词： Carbon fiber reinforced plastics Failure analysis Impact testing Lateral jetting Surface roughness Waterjet

Temperature Effect on the Mechanical Behavior of Acrylic Polymers under Quasi-static and Dynamic Loading

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上海交通大学学报 2004年第Z2期38卷 89-95页

作者： Tao Suo Yulong Li Hong Yu Fei Xu zhongbin tang Lei Li School of Aeronautics Northwestern Polytechnical University Xi''an710072 China School of Aeronautics Northwestern Polytechnical University Xi''an710072 China School of Aeronautics Northwestern Polytechnical University Xi''an710072 China School of Aeronautics Northwestern Polytechnical University Xi''an710072 China School of Aeronautics Northwestern Polytechnical University Xi''an710072 China Beijing Institute of Aeronautical Materials Beijing100095China

In this paper, the mechanical behavior of acrylic polymers at elevated temperature was investigated. Four acrylic polymers were tested at high strain rate by using compression Hopkinson bar and at quasi-static strain rate by using an Instron servo hydraulic axial testing machine with the testing temperature from 218K to 393K. The results show that the mechanical property of acrylic polymers depends heavily on the testing temperature. The yield stress and Young's modulus were found to decrease with increasing temperature at low strain rate. At very low temperature, the materials display typical brittle fracture; however their plasticity improves remarkably at high temperatures. The predictions of the mechanical behavior including the effect of temperature and strain rate using a proposed theoretical model have a good agreement with experimental results.

关键词： acrylic polymer compression Hopkinson bar quasi-static dynamic fracture

Disturbance of plateau zokor-made mound stimulates plant community regeneration in the Qinghai-Tibetan Plateau, China

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Journal of Arid Land 2021年第10期13卷 1054-1070页

作者： XIANG Zeyu Arvind BHATT tang zhongbin PENG Yansong WU Weifeng ZHANG Jiaxin WANG Jingxuan David GALLACHER ZHOU Saixia Lushan Botanical Garden Chinese Academy of SciencesJiujiang 332900China School of Life and Environmental Sciences The University of SydneyNarrabri NSW 2390Australia

Mounds constructed by plateau zokors,which is widely distributed in alpine meadows significantly modified plant community ***,the variations of plant community structure under the disturbance of plateau zokor-made mound are less ***,we investigated the responses of plant community on zokor-made mound of different years(1 a and 3-4 a),and compared with undisturbed sites(no mound)in an alpine meadow in the eastern Qinghai-Tibetan Plateau(QTP),*** richness,coverage and Simpson diversity index were all significantly reduced by the presence of zokor-made mound,but plant heights were significantly increased,particularly in grasses and *** perennial forage species showed an increased importance value and niche breadth,including Koeleria macrantha,Elymus nutans and Poa *** effect of zokor-made mound on niche overlap showed that more intense interspecific competition produced a greater utilization of environmental *** this interspecific niche overlap was strengthened as succession *** bare mound created by zokor burrowing activities provided a colonizing opportunity for non-dominant forage species,resulting in abundant plant species and plant diversity during the succession *** concluded that presence of zokor-made mound was conducive to regeneration and vitality of plant community in alpine meadows,thus improving their resilience to anthropogenic stress.

关键词： rodent mound zokor disturbance alpine meadow vegetation recovery niche

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发动机一级转子抗鸟撞试验与数值模拟研究

航空工程进展 2024年第2期15卷 117-124,141页

作者：王斌宁宇刘军汤忠斌黄福增党蒲妮航空工业第一飞机设计研究院强度设计研究所西安710089 西北工业大学航空学院西安710072 沈阳发动机设计研究所燃烧设计室沈阳110015

鸟撞发动机在鸟撞事故中最容易造成飞机损坏失事的情况,为了研究发动机一级压气机转子抗鸟撞适航性能,对发动机转子在工作状态下进行鸟撞试验,鸟体质量为1000 g,撞击速度为195 m/s,发动机一级转子转速为8525 r/min;基于显式碰撞动力学... 详细信息

鸟撞发动机在鸟撞事故中最容易造成飞机损坏失事的情况,为了研究发动机一级压气机转子抗鸟撞适航性能,对发动机转子在工作状态下进行鸟撞试验,鸟体质量为1000 g,撞击速度为195 m/s,发动机一级转子转速为8525 r/min;基于显式碰撞动力学分析软件PAM-CRASH建立相应的叶片鸟撞数值计算模型,通过与试验结果的对比来验证本文计算模型的合理性;根据发动机适航条例分析不同工况下发动机一级转子抗鸟撞性能。结果表明:大鸟撞击相比于中鸟鸟群和小鸟鸟群,对于叶片的撞击结果更加恶劣;叶尖位置撞击会引起叶尖部位的大变形,叶根和叶中位置撞击会引起叶片根部较大的集中应力,导致叶片断裂。

关键词：发动机叶片鸟撞试验 PAM-CRASH软件数值模拟适航

老年腹腔镜胆囊手术患者术前发生焦虑因素的调查分析

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甘肃医药 2024年第8期43卷 714-716页

作者：张莉燕建洲唐忠斌林菲菲刘锦隆梁吉文兰州市第二人民医院甘肃兰州730000 兰州石化总医院甘肃兰州730060

目的:探讨老年腹腔镜胆囊手术患者术前发生焦虑情绪的影响因素。方法:选择期老年腹腔镜胆囊手术患者385例,根据广泛焦虑障碍量表(GAD-7)评分,将患者分为观察组(焦虑组,GAD-7>5,n=237)和对照组(非焦虑组,GAD-7≤5,n=148),采用多因素Logis... 详细信息

目的:探讨老年腹腔镜胆囊手术患者术前发生焦虑情绪的影响因素。方法:选择期老年腹腔镜胆囊手术患者385例,根据广泛焦虑障碍量表(GAD-7)评分,将患者分为观察组(焦虑组,GAD-7>5,n=237)和对照组(非焦虑组,GAD-7≤5,n=148),采用多因素Logistic回归分析焦虑情绪的影响因素。结果:老年手术患者术前焦虑的发生率为61.6%。Logistic回归分析显示,性别、文化程度、婚姻状况、高血压、害怕术中和术后疼痛及睡眠障碍是引起术前焦虑的独立危险因素。结论:性别、文化程度、婚姻状况、高血压、害怕术中和术后疼痛及睡眠障碍是术前焦虑的影响因素。应重视老年患者术前的心理状态,尽早评估、疏导干预,以促进术后康复。

关键词：老年患者腹腔镜胆囊手术术前焦虑危险因素

2D-C/SiC复合材料低温动态Z向压缩性能

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复合材料学报 2014年第5期31卷 1337-1342页

作者：叶龙海邓琼汤忠斌西北工业大学航空学院西安710072

采用Hopkinson压杆试验装置,对2D-C/SiC复合材料进行了低温条件下的Z向动态压缩性能试验研究,低温条件通过控制酒精和液氮的配比系数得到,通过改变波形整形器几何尺寸的方法来实现恒应变率加载,以得到准确、可信的试验结果。试验结果表... 详细信息

采用Hopkinson压杆试验装置,对2D-C/SiC复合材料进行了低温条件下的Z向动态压缩性能试验研究,低温条件通过控制酒精和液氮的配比系数得到,通过改变波形整形器几何尺寸的方法来实现恒应变率加载,以得到准确、可信的试验结果。试验结果表明:由于复合材料内部含有大量初始微缺陷,2D-C/SiC复合材料在低温动态加载条件下呈现伪塑性行为,其破坏时并未表现出典型的脆性破坏,而是在应力达到压缩强度时出现了显著的应变软化现象,在经历了较大的变形后才最终破坏。随着温度的降低,复合材料的动态Z向压缩强度增加,但失效应变减小。2D-C/SiC复合材料在低温环境下,其内部纤维和基体之间界面结合力增强,同时强的界面结合力可以导致高的压缩强度。

关键词：陶瓷基复合材料 Hopkinson压杆试验装置低温动态Z向压缩力学性能界面强度

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MEMS材料力学性能的测试方法

机械强度 2007年第3期29卷 409-418页

作者：汤忠斌徐绯李玉龙西北工业大学航空学院航空结构工程系西安710072

介绍国内外MEMS(micro-electro-mechanical system)材料力学性能的测试方法,包括纳米压痕法、薄膜打压法、梁弯曲试验、微拉曼光谱法、单轴拉伸法等。分析各种测试方法的优缺点、基本原理和最新进展。详细介绍单轴拉伸试验方法的试验原... 详细信息

介绍国内外MEMS(micro-electro-mechanical system)材料力学性能的测试方法,包括纳米压痕法、薄膜打压法、梁弯曲试验、微拉曼光谱法、单轴拉伸法等。分析各种测试方法的优缺点、基本原理和最新进展。详细介绍单轴拉伸试验方法的试验原理、特点及发展现状,在此基础上介绍作者们在MEMS材料单轴拉伸试验方面的阶段性研究成果,包括单轴拉伸试样设计、夹具设计、加载方法及应变测量技术等。试样和夹具的设计采用有限元方法模拟不同形状参数试样的拉伸试验过程,确定试样的外形和尺寸。应变测量采用的是激光干涉应变计法(interference strain/displacement gauge,ISDG),并用所研制的微小试样拉伸试验机,成功测得多晶铜薄膜材料的应力—应变曲线。

关键词：微电子机械系统力学性能薄膜拉伸激光干涉应变计法

基于波特五力模型的四维动态企业知识创新模式研究

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情报杂志 2007年第8期26卷 25-27页

作者：张少杰汤中彬吉林大学管理学院长春130025

知识创新是企业获得持续竞争优势的源泉,企业知识创新模式是知识管理的核心问题。在分析SECI模型的基础上,分析了基于价值链的知识创新模型的局限,提出了四维动态知识创新模型。

关键词：知识创新 SECI模型知识价值链波特五力模型