Fracture and Structural Integrity最新文献_第5页

Cracking directions in multiaxial low cycle fatigue at high and room temperatures 高温和室温下多轴低周疲劳裂纹方向

Fracture and Structural Integrity Pub Date : 2017-06-28 DOI: 10.3221/IGF-ESIS.41.03

M. Sakane, Takamoto Itoh

引用次数: 0

Study on the effect of new type liquid accelerator on the performance of shotcrete 新型液体促进剂对喷射混凝土性能影响的研究

Fracture and Structural Integrity Pub Date : 2017-06-28 DOI: 10.3221/IGF-ESIS.41.47

Luchen Zhang, Shuchen Li, Q. Yan, Lin Zhu

{"title":"Study on the effect of new type liquid accelerator on the performance of shotcrete","authors":"Luchen Zhang, Shuchen Li, Q. Yan, Lin Zhu","doi":"10.3221/IGF-ESIS.41.47","DOIUrl":"https://doi.org/10.3221/IGF-ESIS.41.47","url":null,"abstract":"Shotcrete is an essential preliminary support means in New Austrian Tunneling Method (NATM) construction and plays a very important role in controlling the stability of surrounding rock. The accelerator is a necessary admixture in shotcrete and its quality can greatly affect shotcrete performance. This paper proposes a new liquid accelerator characterized by short initial and final setting time, small dosage, and good adaptability to cement. Laboratory tests and field tests are conducted to verify the influence of this liquid accelerator on performance of shotcrete. Numerical simulation is carried out to study the strength growth of shotcrete with time and interaction between the strength and stress release of surrounding rock. The results show that the initial and final setting time of this liquid accelerator is 2 minutes and 4 minutes respectively. Its dosage is just 1.5% to 4% of the cement quantity. Adding this liquid accelerator can effectively improve the early strength and reduce the later strength loss of shotcrete, and therefore enhance the supporting effects of shotcrete on surrounding rock. In the field application, it is an ideal liquid accelerator for shotcrete, characterized by little resilience, no slurry shedding, and low dust.","PeriodicalId":300868,"journal":{"name":"Fracture and Structural Integrity","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134233686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Evaluation of new multiaxial damage parameters on low carbon steel 低碳钢多轴损伤新参数的评价

Fracture and Structural Integrity Pub Date : 2017-06-28 DOI: 10.3221/IGF-ESIS.41.08

A. S. Cruces, P. Lopez‐Crespo, B. Moreno, A. Lopez-Moreno, S. Suman

引用次数: 0

Application of Leak-Before-Break concept in 316LN austenitic steel pipes welded using 316L 先漏后破概念在316L焊接316LN奥氏体钢管中的应用

Fracture and Structural Integrity Pub Date : 2017-06-28 DOI: 10.3221/IGF-ESIS.41.44

G. Cunto, A. Andrade, W. Monteiro

{"title":"Application of Leak-Before-Break concept in 316LN austenitic steel pipes welded using 316L","authors":"G. Cunto, A. Andrade, W. Monteiro","doi":"10.3221/IGF-ESIS.41.44","DOIUrl":"https://doi.org/10.3221/IGF-ESIS.41.44","url":null,"abstract":"The paper presents a study of the application of Leak-Before- Break (LBB) concept in a relatively small-diameter high energy reactor coolant line, where it is proposed type AISI 316LN to be used as base material welded with type AISI 316L coated electrode considering a pipe with diameter of 273 mm. The pipe material was characterized in terms of tensile test with Ramberg-Osgood analyses and fracture toughness tests with J-Resistance curve determination, considering base material, weld joint and heat affected zones. For the mechanical properties found in tensile tests and using the PICEP software, were determined the leak rate curves versus crack sizes, to determine the size of a detectable leakage crack, and the critical crack sizes, considering failure by plastic collapse. For the critical crack sizes found in weld, which presented the lowest toughness, J-Integral analysis was performed considering failure by tearing instability. Results show a well-defined mechanical behavior where base material has a high toughness, weld has a low toughness, and HAZ showed intermediate properties. For the load limit analysis, the lowest critical crack size was found for base material presenting circumferential cracks. For J- Integral analysis, it was demonstrated that failure by tearing instability will not occur.","PeriodicalId":300868,"journal":{"name":"Fracture and Structural Integrity","volume":"152 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120972868","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Cracked components under anti-plane loading: recent outcomes and future developments 反平面荷载下的裂纹构件:最新研究成果及未来发展

Fracture and Structural Integrity Pub Date : 2017-06-28 DOI: 10.3221/IGF-ESIS.41.59

F. Berto

{"title":"Cracked components under anti-plane loading: recent outcomes and future developments","authors":"F. Berto","doi":"10.3221/IGF-ESIS.41.59","DOIUrl":"https://doi.org/10.3221/IGF-ESIS.41.59","url":null,"abstract":"The existence of three-dimensional effects at cracks has been known for many years, but understanding has been limited, and for some situations still is. Understanding improved when the existence of corner point singularities and their implications became known. Increasingly powerful computers made it possible to investigate three-dimensional effects numerically in detail. Despite increased understanding, three-dimensional effects are sometimes ignored in situations where they may be important. The purpose of the present investigation is to study by means of accurate 3D finite element (FE) models a coupled fracture mode generated by anti-plane loading of a straight through-the-thickness crack in linear elastic plates. An extended version of the present work has recently been published in the literature. The results obtained from the highly accurate finite element analyses have improved understanding of the behaviour of through cracked components under anti-plane loading. The influence of plate bending is increasingly important as the thickness decreases. It appears that a new field parameter, probably a singularity, is needed to describe the stresses at the free surfaces. Discussion on whether KIII tends to zero or infinity as a corner point is approached is futile because KIII is meaningless at a corner point. The intensity of the local stress and strain state through the thickness of the cracked components has been evaluated by using the strain energy density (SED) averaged over a control volume embracing the crack tip. The SED has been considered as a parameter able to control fracture in some previous contributions and can easily take into account also coupled three-dimensional effects. Calculation of the SED shows that the position of the maximum SED is independent of plate thickness. Both for thin plates and for thick ones the maximum SED is close to the lateral surface, where the maximum intensity of the coupled mode II takes place.","PeriodicalId":300868,"journal":{"name":"Fracture and Structural Integrity","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127720247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Influence of forging conditions on the fatigue mechanisms of low alloy steels: a 3D study 锻造条件对低合金钢疲劳机制的影响:三维研究

Fracture and Structural Integrity Pub Date : 2017-06-28 DOI: 10.3221/IGF-ESIS.41.26

P. Lorenzino, J. Buffière, C. Verdu

引用次数: 0

Notched multiaxial fatigue of Al7050-T7451: on the need for an equivalent process zone size Al7050-T7451的缺口多轴疲劳:对等效工艺区尺寸的需求

Fracture and Structural Integrity Pub Date : 2017-06-28 DOI: 10.3221/IGF-ESIS.41.13

M.V.C. Sá, J. Ferreira, C. Silva, J. A. Araújo

引用次数: 4

Residual welding stress of I-section members beyond the limits of width-thickness ratio 工字型钢构件的焊接残余应力超过宽厚比限值

Fracture and Structural Integrity Pub Date : 2017-06-28 DOI: 10.3221/IGF-ESIS.41.49

Zhiyuan Li, Zhiyun Zhao

引用次数: 0

Fracture toughness of rough and frictional cracks emanating from a re-entrant corner 粗糙裂纹和摩擦裂纹的断裂韧性

Fracture and Structural Integrity Pub Date : 2017-06-28 DOI: 10.3221/IGF-ESIS.41.24

A. Carpinteri, A. Spagnoli, M. Terzano, S. Vantadori

引用次数: 5

Experimental evaluation of CTOD in constant amplitude fatigue crack growth from crack tip displacement fields 裂纹尖端位移场对恒幅疲劳裂纹扩展CTOD的实验评价

Fracture and Structural Integrity Pub Date : 2017-06-28 DOI: 10.3221/IGF-ESIS.41.22

J. Vasco‐Olmo, F. Díaz, F. Antunes, M. James

{"title":"Experimental evaluation of CTOD in constant amplitude fatigue crack growth from crack tip displacement fields","authors":"J. Vasco‐Olmo, F. Díaz, F. Antunes, M. James","doi":"10.3221/IGF-ESIS.41.22","DOIUrl":"https://doi.org/10.3221/IGF-ESIS.41.22","url":null,"abstract":"In the current work an experimental study of the crack tip opening displacement (CTOD) is performed to evaluate the ability of this parameter to characterise fatigue crack growth. A methodology is developed to measure and to analyse the CTOD from experimental data. The vertical displacements measured by implementing Digital Image Correlation on growing fatigue cracks are used to measure the CTOD. Fatigue tests at R ratios of 0.1 and 0.6 were conducted on compact-tension specimens manufactured from commercially pure titanium. A sensitivity analysis was performed to explore the effect of the position selected behind the crack tip for the CTOD measurement. The analysis of a full loading cycle allowed identifying the elastic and plastic components of the CTOD. The plastic CTOD was found to be directly related to the plastic deformation at the crack tip. Moreover, a linear relationship between da/dN and the plastic CTOD for both tests was observed. Results show that the CTOD can be used as a viable alternative to ?K in characterising fatigue crack propagation because the parameter considers fatigue threshold and crack shielding in an intrinsic way. This work is intended to contribute to a better understanding of the different mechanisms driving fatigue crack growth and the address the outstanding controversy associated with plasticity-induced fatigue crack closure.","PeriodicalId":300868,"journal":{"name":"Fracture and Structural Integrity","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116512057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 13