Frattura ed Integrità Strutturale最新文献_第2页

About Measuring the Stress Intensity Factor of Cracks in Curved, Brittle Shells 关于测量曲面脆壳裂缝的应力强度因子

Frattura ed Integrità Strutturale Pub Date : 2024-04-13 DOI: 10.3221/igf-esis.69.01

A. Sipos, Siwen Cao

引用次数: 0

Titanium/FRP hybrid sandwich: in-plane flexural behaviour of short beam specimens 钛/玻璃纤维增强塑料混合夹层：短梁试样的面内弯曲性能

Frattura ed Integrità Strutturale Pub Date : 2024-04-13 DOI: 10.3221/igf-esis.69.02

C. Bellini, R. Borrelli, V. Di Cocco, S. Franchitti, Francesco Iacoviello, L. P. Mocanu, L. Sorrentino

{"title":"Titanium/FRP hybrid sandwich: in-plane flexural behaviour of short beam specimens","authors":"C. Bellini, R. Borrelli, V. Di Cocco, S. Franchitti, Francesco Iacoviello, L. P. Mocanu, L. Sorrentino","doi":"10.3221/igf-esis.69.02","DOIUrl":"https://doi.org/10.3221/igf-esis.69.02","url":null,"abstract":"Adopting novel sandwich structures with FRP (Fibre Reinforced Polymer) skins and a metallic lattice core, both of which have high specific strength and stiffness, is one way to achieve better mechanical performance while remaining lightweight. Flexural stress is a load pattern that frequently occurs in the structural frame components of automobiles; nonetheless, while the in-plane load scheme has scarcely been examined, the out-of-plane load one has. As a result, the former configuration received consideration in this work. Moreover, short beam specimens were taken into account. The mechanical response of specimens with three different kinds of composite materials as skin material was analysed. The skins were made of CFRP (Carbon Fiber Reinforced Polymer), with two different weaving styles, and AFRP (Aramid Fiber Reinforced Polymer). All-titanium specimens were studied, too. Similar maximum loads and maximum displacement at break were recorded for both CFRP and AFRP specimens, while the all-titanium one resulted stronger. In terms of the load-displacement curves, the first section featured an initial linear phase, followed by a minor load drop, likely attributed to the breakage of fibres. The CFRP specimens showed a sharp fracture of the skin fibres, while for the AFRP, a fraying was observed.","PeriodicalId":507970,"journal":{"name":"Frattura ed Integrità Strutturale","volume":"61 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140708225","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

Assessing structural integrity of non-homogeneous systems by means of Acoustic Emissions and Non-Extensive Statistical Mechanics 利用声发射和非广延性统计力学评估非均质系统的结构完整性

Frattura ed Integrità Strutturale Pub Date : 2024-03-28 DOI: 10.3221/igf-esis.68.29

S. Kourkoulis, E. Pasiou, Ilias Stavrakas, D. Triantis

{"title":"Assessing structural integrity of non-homogeneous systems by means of Acoustic Emissions and Non-Extensive Statistical Mechanics","authors":"S. Kourkoulis, E. Pasiou, Ilias Stavrakas, D. Triantis","doi":"10.3221/igf-esis.68.29","DOIUrl":"https://doi.org/10.3221/igf-esis.68.29","url":null,"abstract":"Taking advantage of the interevent time intervals, namely the time intervals between two successive acoustic events recorded during mechanical loading of structural elements, it is attempted to detect indices warning about upcoming failure. The innovative aspect of the study is that the analysis is implemented in the frame of Non-Extensive Statistical Mechanics, a discipline founded on a class of entropies violating the additivity principle, which is the cornerstone of the Boltzmann-Gibbs Statistical Mechanics. The specimens used for the experiments were marble blocks simulating either fragmented and restored epistyles or mutually interconnected intact epistyles of the Parthenon Temple on the Acropolis of Athens. The specimens consisted of three materials (marble, metallic connectors and cementitious pastes) exhibiting, thus, a strongly non-homogeneous nature. The entropic index, i.e., the parameter quantifying the degree of non-additivity, was used for the analysis of the experimental data. The results were considered in juxtaposition to the respective ones from experimental protocols with specimens of macroscopically homogeneous nature. It was concluded that the temporal evolution of the entropic index provides very good insight into the level of damage accumulated in the loaded structure, independently of whether the structure is homogeneous or not, providing an interesting pre-failure indicator.","PeriodicalId":507970,"journal":{"name":"Frattura ed Integrità Strutturale","volume":"58 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140368975","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

Degradation analysis of dynamic properties for plain concrete structures under mixed-mode fracture conditions via an improved cohesive crack approach 通过改进的内聚裂缝方法分析混合模式断裂条件下素混凝土结构的动态性能退化情况

Frattura ed Integrità Strutturale Pub Date : 2024-03-26 DOI: 10.3221/igf-esis.68.28

U. De Maio, D. Gaetano, F. Greco, Raimondo Luciano, A. Pranno

引用次数: 0

Phenomenon of ignition and explosion of high-entropy alloys of systems Ti-Zr-Hf-Ni-Cu, Ti-Zr-Hf-Ni-Cu-Co under quasi-static compression 准静态压缩下 Ti-Zr-Hf-Ni-Cu 和 Ti-Zr-Hf-Ni-Cu-Co 系高熵合金的点火和爆炸现象

Frattura ed Integrità Strutturale Pub Date : 2024-03-25 DOI: 10.3221/igf-esis.68.27

O. Zatsarna, Sergiy Kotrechko, Oleksandr Filatov, Vadim Bondarchuk, Georgiy Firstov, Vladimir Dubinko

{"title":"Phenomenon of ignition and explosion of high-entropy alloys of systems Ti-Zr-Hf-Ni-Cu, Ti-Zr-Hf-Ni-Cu-Co under quasi-static compression","authors":"O. Zatsarna, Sergiy Kotrechko, Oleksandr Filatov, Vadim Bondarchuk, Georgiy Firstov, Vladimir Dubinko","doi":"10.3221/igf-esis.68.27","DOIUrl":"https://doi.org/10.3221/igf-esis.68.27","url":null,"abstract":"The phenomenon of ignition and explosive failure of specimens from high-entropy alloys (HEAs) of systems Ti-Zr-Hf-Ni-Cu, Ti-Zr-Hf-Ni-Cu-Co at quasi-static compression tests was found. It physical model is proposed. It is exhibited that the reason for this phenomenon is the release of energy of the oxidation reaction; such reaction is initiated due to the heat released ahead of the shear crack tip at brittle fracture of the specimens under quasi-static compression. It is shown that ignition and failure by explosion are the specific features of brittle fracture for high-entropy alloys containing Ti-Zr-Hf, in general. This phenomenon is realised when certain critical levels of strength and ductility of these alloys are reached. The importance of these critical levels of strength and ductility lies in the fact that they predetermine the maximum permissible level of strength and brittleness for this class of HEAs, above which they lose their structural and functional properties, turning to the energetic alloys capable of explosive release of a significant amount of thermal energy. This specific feature of the high-entropy alloys containing Ti-Zr-Hf outlines the scope of their application and defines the boundary separating structural and functional high-entropy alloys from energetic high-entropy alloys.","PeriodicalId":507970,"journal":{"name":"Frattura ed Integrità Strutturale","volume":" 90","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140384559","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

Ultrasonic welding of lap joints of PEI plates with PEI/CF-fabric prepregs 用超声波焊接 PEI 板与 PEI/CF 纤维预浸料的搭接接头

Frattura ed Integrità Strutturale Pub Date : 2024-03-15 DOI: 10.3221/igf-esis.68.26

V. Alexenko, Defang Tian, Sergey V. Panin, Svetlana Bochkareva, Iliya Panov

{"title":"Ultrasonic welding of lap joints of PEI plates with PEI/CF-fabric prepregs","authors":"V. Alexenko, Defang Tian, Sergey V. Panin, Svetlana Bochkareva, Iliya Panov","doi":"10.3221/igf-esis.68.26","DOIUrl":"https://doi.org/10.3221/igf-esis.68.26","url":null,"abstract":"In this study, ultrasonic welding (USW) of lap joints of polyetherimide (PEI) plates (adherends) with carbon fiber (CF) prepregs impregnated with PEI was investigated. No energy director (ED) was used, so binder contents were varied in the prepregs to compensate for the lack of the polymer in the fusion zone. In addition, the effect of the USW parameters on the structure and the mechanical properties of the lap-joints were analyzed. The most homogeneous macrostructure, the maintained structural integrity of both the CF-fabric in the prepregs and the lap-joined PEI adherends, as well as the maximum strength properties (tensile strength) were revealed for the USW joints with the minimum polymer content in the prepreg. In this case, rising the USW time from 400 up to 800 ms radically changed the macrostructure of the fusion zone, while the strength properties did not vary significantly (shear stresses were 42–48 MPa). Computer simulation of the influence of the PEI/CF-fabric ratios in the prepregs on the deformation response of the USW joints showed that the prepreg thicknesses and, accordingly, the PEI/CF ratios did not exert a noticeable effect on the strain–stress (tensile) diagrams, while the determining factor was the adhesion level.","PeriodicalId":507970,"journal":{"name":"Frattura ed Integrità Strutturale","volume":"3 9","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140239267","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

On the stress- and strain-based fatigue behavior of welded thick-walled nodular cast iron 基于应力和应变的焊接厚壁球墨铸铁疲劳行为

Frattura ed Integrità Strutturale Pub Date : 2024-03-15 DOI: 10.3221/igf-esis.68.25

C. Bleicher, Steffen Schoenborn, Heinz Kaufmann, M. Alizadeh-Sh

{"title":"On the stress- and strain-based fatigue behavior of welded thick-walled nodular cast iron","authors":"C. Bleicher, Steffen Schoenborn, Heinz Kaufmann, M. Alizadeh-Sh","doi":"10.3221/igf-esis.68.25","DOIUrl":"https://doi.org/10.3221/igf-esis.68.25","url":null,"abstract":"Nodular cast iron (GJS) represents one of the most widely used materials for vehicle, energy and heavy machinery industry. Nevertheless, foundries struggling with the influence of local material defects in GJS like pores, shrinkages and dross often leading to a locally reduced fatigue strength of the entire component. One measure to tackle those negative effects is the welding of the affected areas. This measure is then successful when locally achieved material strengths and surface qualities are higher than the component with the casting defect. Unfortunately, data for the lifetime and fatigue assessment of welded GJS are not present right now. Thus, the research project »nodularWELD« assessed the local stress- and strain-based fatigue data of different thick-walled GJS grades for building a basis for a successful usage even of defect affected components. So, three ferritic and pearlitic GJS grades were investigated in the heat-affected zone, the base material, the welding filler and more over in an integral material state comprising all those three aforementioned states based on axial and bending investigations. Additionally metallographic and fractographic analysis were conducted.","PeriodicalId":507970,"journal":{"name":"Frattura ed Integrità Strutturale","volume":"2 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140237237","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

Interpretation of fatigue lifetime prediction by machine learning modeling in piston aluminum alloys under different manufacturing and loading conditions 通过机器学习建模解读不同制造和加载条件下活塞铝合金的疲劳寿命预测

Frattura ed Integrità Strutturale Pub Date : 2024-03-11 DOI: 10.3221/igf-esis.68.24

Mohammad Azadi, Mahmood Matin

引用次数: 0

Predictive Modeling of Fracture Behavior in Ti6Al4V Alloys Manufactured by SLM Process 利用 SLM 工艺制造的 Ti6Al4V 合金断裂行为预测模型

Frattura ed Integrità Strutturale Pub Date : 2024-03-10 DOI: 10.3221/igf-esis.68.23

Mohsen Sarparast, M. Shafaie, Mohammad Davoodi, Ahmad Memaran Babakan, Hongyan Zhang

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Fracture processes numerical modeling of elastic-brittle bodies with statistically distributed subregions strength values 具有统计分布式子区域强度值的弹性脆性体的断裂过程数值建模

Frattura ed Integrità Strutturale Pub Date : 2024-03-05 DOI: 10.3221/igf-esis.68.22

Eugeniia Feklistova, A. Mugatarov, V. Wildemann, Anton Agishev

引用次数: 0