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Experimental investigations of the influence of thickness and mixed mode loading on the crack initial angle in LC4-CS aluminum

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Experimental investigations of the influence of thickness an...

Rate Dependence of Interlaminar Fracture Toughness in Carbon-Fiber/Epoxy Composite Laminates under mixed mode Loading

ICEM 2001 The 3～(rd) International Conference on Experimental Mechanics

＜正＞ mixed mode fracture is one of the most common failure forms of materials in practical engineering. In the past, 2D crack initiation problems under mixed-mode I and II loading conditions have attracted much attention. Through many investigations, a number of fracture criteria for predicting the onset of fracture and the direction of crack initiation tinder mixed-mode I and II crack tip loading conditions have been well established, including the maximum tangential stress criterion （MTS-criterion）, the maximum energy release rate criterion, the minimum strain energy density factor criterion, and the maximum stress triaxiality criterion （M-criterion）. Nonetheless, there is lack of systematic studies on the relation between the crack initial angle and plate thickness insufficiently understood. In this paper, crack initial angle in LC4-CS aluminum plates is investigated experimentally using compact-tension-shear type specimens with various thickness 2, 4, 8 and 14 mm, respectively. The aim is to elucidate the effect of thickness on crack initial angle in aluminum plates and provide a good experimental foundation for revealing three-dimensional failure law and establishing three-dimensional fracture criterion of aluminum alloy under mixed mode loading *** specimen was loaded in a displacement-controlled MTS 810 100kN testing machine at a constant crosshead rate of 0.4 mm/min. Clip-gauge was mounted for measurement of crack opening displacement （CMOD） during final loading. Traces of load versus opening displacement were recorded for each test. Data were captured using the TestStar computer-testing system which triggered every 0.05 mm of displacement. After broken specimens were sectioned into halves at the mid-thickness, crack initiation directions were measured with a universal bevel *** results of the crack initial angle for various thickness plates and mixed load modes were obtainted and compared with theoretical predictions from MTS-cr

关键词： mixed mode crack initiation fracture criterion thickness effect aluminum alloy

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Rate Dependence of Interlaminar Fracture Toughness in Carbon...

A Nano-Cantilever Method for Crack Initiation at the Free Edge of the Cu/Si Interface in Nanoscale Components

第十三届国际复合材料会议

作者： Noriyo Hori kawa Takayuki Kusaka Masayoshi Masuda New Energy and Industrial Technology Development Organization 1-1-1 Noji-Higashi Kusatsu 525-8577 Japan Department of Mechanical Engineering Ritsumeikan University 1-1-1 Noji-Higashi Kusatsu 525-8577 Japan Graduate Student Ritsumeikan University 1-1-1 Noji-Higashi Kusatsu 525-8577 Japan

＜正＞mixed mode interlaminar fracture behavior of several types of carbon-fiber/epoxy composites was investigated to clarify the effects of strain rate and mode ratio. The mode Ⅰ, mode Ⅱ and their mixed mode fracture toughness showed strain rate dependence regardless of mode ratio. The mixed mode fracture toughness conformed to the linear fracture criterion at lower loading rate. However, it did not conform to the linear criterion at higher loading rate.

关键词： delamination mixed mode fracture toughness fracture criterion rate dependence impact strength

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Acta Mechanica Solida Sinica 2016年第4期29卷 416-428页

作者： Xiaoyuan Wang Yabin Yan Qiang Wan Takashi Sumigawa Takayuki Kitamura Institute of Systems Engineering China Academy of Engineering Physics Department of Mechanical Engineering and Science Kyoto University

Straight and Bent nano-cantilever specimens are respectively proposed to investigate the single-mode and mixed-mode crack initiation at the Cu/Si interface edge in nanoscale components. With a minute loading apparatus, all nanoscale samples are in situ loaded and observed. Numerical analysis is employed to acquire the critical interfacial stress distributions during crack initiation. The stress concentration regions near the edge of Cu/Si interface in all specimens are within the scale of 100 nm, and the critical normal and shear stresses have a circular relation in nanoscale components, which represents the fracture criterion of the interface in nanoscale components.

关键词： nanoscale cantilever interface crack initiation mixed mode thin film

Self-trapping under two-dimensional spin-orbit coupling and spatially growing repulsive nonlinearity

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Frontiers of physics 2018年第4期13卷 259-274页

作者： Rong-Xuan Zhong Zhao-Pin Chen Chun-Qing Huang Zhi-Huan Luo Hai-Shu Tan Boris A. Malomed Yong-Yao Li School of Physics and Optoelectronic Engineering Foshan University Foshan 528000 China Department of Physical Electronics School of Electrical Engineering Faculty of Engineering Tel Aviv University Tel Aviv 69978 Israel College of Electronic Engineering South China Agricultural University Guangzhou 510642 China ITMO University St. Petersburg 197101 Russia

We develop a method for creating two- and one-dimensional （2D and 1D） self-trapped modes in bi- nary spin-orbit-coupled Bose-Einstein condensates with the contact repulsive interaction, whose local strength grows sufficiently rapidly from the center to the periphery. In particular, an exact semi-vortex （SV） solution is found for the anti-Gaussian radial modulation profile. The exact modes are included in the numerically produced family of SV solitons. Other families, in the form of mixed modes （MMs）, as well as excited states of SVs and MMs, are also produced. Although the excited states are unstable in all previously studied models, they are partially stable in the present one. In the 1D version of the system, exact solutions for the counterpart of SVs, namely, semi-dipole solitons, are also found. Families of semi-dipoles, as well as the 1D version of MMs, are produced numerically.

关键词： spin-orbit coupling semi-vortex mixed mode excited states

Ionic Liquid 1-Vinyl-3-dodecylimidazole Bromide Embedded Hybrid Monolithic Column and Its Versatile Post-modification with Amino Acids

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Journal of Analysis and Testing 2021年第4期5卷 387-395页

作者： Yufeng Zhou Liguang Duan Yixin Huang Yaqi Liu Lijuan Wang Xiaoqiang Qiao College of Pharmaceutical Sciences Key Laboratory of Public Health Safety of Hebei ProvinceHebei UniversityBaoding 071002China Key Laboratory of Medicinal Chemistry and Molecular Diagnosis Ministry of EducationInstitute of Life Science and Green DevelopmentHebei UniversityBaoding 071002China The First Hospital of Hebei Medical University Shijiazhuang 050031China

The amino acids post-modified ionic liquids-based hybrid monolithic columns were successfully *** the first step,using 1-vinyl-3-dodecylimidazole bromide(VDI·Br)and polyhedral oligomeric silsesquioxane methacryl substituted(POSS-MA)as monomer and crosslinking agent,the monolithic POSS-VDI matrix material was polymerized in 100μm *** prepared POSS-VDI column is of ion-exchange/reverse-phase mixed-mode retention *** column e fficiency reached 137,000 N/m for *** POSS-VDI column has also been successfully applied to recognize and analyze the eff ective components of Traditional Chinese Medicines Fangji and the Root of Kudzu ***,based on its good chromatographic performances,in the second step,amino acids L-Proline(L-Pro),Glycine(Gly)or DLPhenylalanine(DL-Phe)were further exploited as the anion exchangers to post-modify the POSS-VDI *** new POSS-VDI-Pro,POSS-VDI-Gly and POSS-VDI-Phe columns exhibited diff erent separation selectivity for the complex egg white protein *** present work provides a good route to fabricate versatile amino acids and ionic liquids modified monolithic columns with good separation selectivity.

关键词： Monolithic column Chromatographic separation Polyhedral oligomeric silsesquioxane Amino acid and ionic liquids mixed mode

IMPROVED COHESIVE ZONE modeL AND ITS APPLICATION IN INTERFACE CONTACT ANALYSIS

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Acta Metallurgica Sinica(English Letters) 2008年第4期21卷 295-302页

作者： Y. Wang J. Chen H.B. Li National Die ＆ Mold CAD Engineering Research Center Shanghai Jiaotong University Shanghai 200030China

An improved interface cohesive zone model is developed for the simulation of interface contact, under mixed-mode loading. A new debonding initiation criterion and propagation of debonding law, taking into account the pressure stress influence on contact shear strength, is proposed. The model is implemented in a finite-element program using subroutine VUINTER of ABAQUS Explicit. An edge-notch four-point bending process and laminated vibration damping steel sheet punch forming test are simulated with the improved model in ABAQUS Explicit. The numerical predictions agree satisfactorily with the corresponding experimental results.

关键词： Cohesive zone model mixed mode Damage criterion Contact stress

Separation of Basic Drugs Using Pressurized Capillary Electrochromatography

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Chinese Journal of Chemistry 2003年第4期21卷 419-422页

作者：张锴阎超姚传义江正瑾张智超王琴孙高如瑜 State Key Laboratory of Elemento Organic Chemistry Nankai University Unimicro Technologies Inc. 4713 First Street Pleasanton

A novel pressurized capillary electrochromatography (PCEC) was developed to separate basic drugs on strong cation exchange (SCX) column. The separation result by using PCEC was better than that by using micro-HPLC. The effects of electrical field and pressure on plate height and resolution were investigated. Influences of organic modifier, ionic strength and pH value of buffer on retention behavior were evaluated, and the separation mechanism was also discussed.

关键词： pressurized capillary electrochromatography strong cation exchange mixed mode basic drug