Procedia Structural Integrity最新文献_第10页

Cyclic-elastic behavior in plastically pre-strained lattice structures 塑性预应变晶格结构的循环弹性行为

Procedia Structural Integrity Pub Date : 2025-01-01 DOI: 10.1016/j.prostr.2025.06.105

Ivan Senegaglia , Giuseppe Macoretta , Tommaso Grossi , Bernardo Disma Monelli

{"title":"Cyclic-elastic behavior in plastically pre-strained lattice structures","authors":"Ivan Senegaglia , Giuseppe Macoretta , Tommaso Grossi , Bernardo Disma Monelli","doi":"10.1016/j.prostr.2025.06.105","DOIUrl":"10.1016/j.prostr.2025.06.105","url":null,"abstract":"<div><div>The study investigates the evolution of elastic behavior in lattice structures subjected to cyclical loading after pre-straining to various levels of plastic deformation. Triply Periodic Minimal Surface (TPMS) gyroid lattice specimens were fabricated using the Laser Powder Bed Fusion (L-PBF) technique and subjected to controlled steps of compressive pre-straining, inducing plastic deformations. Subsequently, the specimens underwent cyclic loading-unloading tests to characterize their elastic behavior. Stress-strain curves were monitored throughout the testing to determine the apparent elastic modulus (<em>E</em>*) at each cycle. The results demonstrate that E* of pre-strained lattices are not static. The initial cycles after pre-straining exhibit a change in stiffness, with the <em>E</em>* initially increasing depending on the pre-strain level. This behavior is attributed to the morphology of the lattice itself, which is more sensible to local hardening due to an evident bending-dominated mechanical response. Over slight plastic strains, the elastic modulus stabilizes, reaching a new stiffening-to-plastic strain evolution. The magnitude of this shift and the experimental response’s dispersion are found to not be dependent on the pre-strain level.</div></div>","PeriodicalId":20518,"journal":{"name":"Procedia Structural Integrity","volume":"68 ","pages":"Pages 610-618"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144580338","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}

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The microstructure and fracture mode of physically simulated heat-affected zones of a weld metal used with 500 MPa offshore steel – part 2: fractographies, inclusions and microstructures 500mpa海上钢用焊接金属热影响区的物理模拟显微组织和断裂模式。第2部分：断口学、夹杂物和显微组织

Procedia Structural Integrity Pub Date : 2025-01-01 DOI: 10.1016/j.prostr.2025.06.089

Henri Tervo , Marcell Gáspár , Judit Kovács , Antti Kaijalainen , Vahid Javaheri , Johannes Sainio , Jukka Kömi

{"title":"The microstructure and fracture mode of physically simulated heat-affected zones of a weld metal used with 500 MPa offshore steel – part 2: fractographies, inclusions and microstructures","authors":"Henri Tervo , Marcell Gáspár , Judit Kovács , Antti Kaijalainen , Vahid Javaheri , Johannes Sainio , Jukka Kömi","doi":"10.1016/j.prostr.2025.06.089","DOIUrl":"10.1016/j.prostr.2025.06.089","url":null,"abstract":"<div><div>Welded joints in 500 MPa offshore steels are often the weakest points in structures, and multiple welding passes for thick sections can affect the microstructure of the weld metal. While much research focuses on heat-affected zones (HAZ) in the base metal, this study examines the HAZ in the weld metal, comparing the original weld’s microstructure, inclusions, and fracture modes to simulated coarse-grained (CGHAZ-W) and intercritical HAZs (ICHAZ-W) in the weld metal. The original weld was produced using submerged arc welding, and HAZs with different cooling times (t<sub>8/5</sub> = 5, 15, 30 s) were simulated using a Gleeble 3500 thermomechanical simulator. Microstructural analysis, inclusion measurements, and fractography were performed using a field emission scanning electron microscope. The results showed that thermal cycles altered the microstructure of CGHAZ-W and ICHAZ-W compared to the original weld. The shortest cooling time (t<sub>8/5</sub> = 5 s) led to slight hardening in CGHAZ-W. Inclusions, mainly oxides or oxysulfides, increased significantly in CGHAZ-W, but not in ICHAZ-W. Most samples exhibited ductile fractures, with microvoid nucleation, although local brittle regions were detected, linked to grain boundary ferrite and side-plate ferrite in an acicular ferritic matrix.</div></div>","PeriodicalId":20518,"journal":{"name":"Procedia Structural Integrity","volume":"68 ","pages":"Pages 506-512"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144580419","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}

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Electrical resistance-based fatigue damage assessment of steels 基于电阻的钢的疲劳损伤评估

Procedia Structural Integrity Pub Date : 2025-01-01 DOI: 10.1016/j.prostr.2025.06.078

Lukas M. Sauer , Johannes L. Otto , Lars A. Lingnau , Jonas A. Ziman , Peter Starke , Frank Walther

{"title":"Electrical resistance-based fatigue damage assessment of steels","authors":"Lukas M. Sauer , Johannes L. Otto , Lars A. Lingnau , Jonas A. Ziman , Peter Starke , Frank Walther","doi":"10.1016/j.prostr.2025.06.078","DOIUrl":"10.1016/j.prostr.2025.06.078","url":null,"abstract":"<div><div>Electrical resistance measurements are a common method for the characterization of various microstructural properties and damage mechanisms, e.g., dislocation density, void volume fraction and microcracks. Additionally, influence affecting the electrical resistance, such as specimen geometry or temperature, must be considered. Therefore, ex-situ measurement techniques are frequently employed during fatigue due to their simpler measurement. However, ex-situ investigations have the potential to result in unintended influences due to disruptions, and only discrete states are analyzed limiting the characterization. Consequently, in-situ measurements were performed in this study to investigate damage mechanisms and evolution during fatigue loading. To quantify and compensate for the influence of geometry, temperature, and martensite volume fraction change during fatigue tests, a complex experimental setup was developed for in-situ electrical resistance measurements. A new developed combination of measurement systems enables the direct transfer of measured strain to electrical resistance. The method was tested on high-temperature vacuum brazed joints with a metastable austenite as base material and Ni-based filler metal. Finally, the change of the microstructure was evaluated through scanning electron microscopy analyses at different load cycles.</div></div>","PeriodicalId":20518,"journal":{"name":"Procedia Structural Integrity","volume":"68 ","pages":"Pages 432-438"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144580408","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

Effects of Pressurized Water Reactor Environment and Cyclic Loading Parameters on the Low Cycle Fatigue Behavior of 316L Stainless Steel 压水堆环境和循环加载参数对316L不锈钢低周疲劳行为的影响

Procedia Structural Integrity Pub Date : 2025-01-01 DOI: 10.1016/j.prostr.2025.06.054

Aleks Vainionpää , Zaiqing Que , Tommi Seppänen

引用次数: 0

Failure assessment through various uncoupled damage models in flow forming processes 流动成形过程中各种不耦合损伤模型的失效评估

Procedia Structural Integrity Pub Date : 2025-01-01 DOI: 10.1016/j.prostr.2025.06.061

Tuncay Yalçinkaya , Hande Vural , Tevfik Ozan Fenercioğlu

{"title":"Failure assessment through various uncoupled damage models in flow forming processes","authors":"Tuncay Yalçinkaya , Hande Vural , Tevfik Ozan Fenercioğlu","doi":"10.1016/j.prostr.2025.06.061","DOIUrl":"10.1016/j.prostr.2025.06.061","url":null,"abstract":"<div><div>Flow forming is a unique metal forming process that utilizes specially designed rollers and a mandrel to shape metal parts with high dimensional accuracy and structural integrity, especially for thin-walled, seamless tubes. Due to the incremental nature of the process, material is subjected to complex stress states and significant plastic deformation that can lead to many types of defects and cracks, and therefore it is crucial to make accurate forming limit predictions to optimize the manufacturing process. This study investigates the capabilities of uncoupled damage models in predicting fracture initiation and formability limits during the flow forming of IN718 alloy. In this regards ten different damage criteria are employed in Finite Element (FE) simulations including Ayada, Ayada-m, Brozzo, KH, Le-Roy (LR), McClintock (MC), Oh (OH), Rice-Tracey (RT), which are calibrated with tensile tests. Subsequently, these models are applied to flow forming simulations at varying thickness reduction ratios (37.5%, 50% and 70%). The results are compared with experimental trials to assess the prediction accuracy of each model regarding formability limits and fracture initiation. The initial investigations demonstrate that the Ayada criteria are better in predicting damage at all reduction ratios compared to other criteria, making them particularly suitable for this process. In addition, the KH model gives comparable predictions, although it is not successful at all reduction ratios.</div></div>","PeriodicalId":20518,"journal":{"name":"Procedia Structural Integrity","volume":"68 ","pages":"Pages 325-331"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144580721","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}

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Examining the Role of Cell Structures in the Mechanical and Vibration Characteristics of 3D Printed Parts 研究细胞结构在3D打印部件的机械和振动特性中的作用

Procedia Structural Integrity Pub Date : 2025-01-01 DOI: 10.1016/j.prostr.2025.06.062

Büşra Eyri, Bartu Türkcan Çetin, Fevzi Çakmak Bolat, Taner Yılmaz

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The brittle fracture of bodies with partially healed surface cracks 表面裂纹部分愈合的体的脆性断裂

Procedia Structural Integrity Pub Date : 2025-01-01 DOI: 10.1016/j.prostr.2025.06.016

Ivan Shatskyi, Vasyl Perepichka, Taras Dalyak

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Performance evaluation of artificial neural networks developed for estimation of fatigue behavior of low-alloy steels 基于人工神经网络的低合金钢疲劳性能评价

Procedia Structural Integrity Pub Date : 2025-01-01 DOI: 10.1016/j.prostr.2025.06.026

Tea Marohnić , Robert Basan

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Compressive strength of high-strength concrete modified with synthetic fibers at elevated temperatures 高温下合成纤维改性高强混凝土的抗压强度

Procedia Structural Integrity Pub Date : 2025-01-01 DOI: 10.1016/j.prostr.2025.06.051

Rami Hawileh , Ahmed Selim , Maha Assad , Jamal Abdalla , Abdulrahman Mohamed , Abdulrahman Madkour

{"title":"Compressive strength of high-strength concrete modified with synthetic fibers at elevated temperatures","authors":"Rami Hawileh , Ahmed Selim , Maha Assad , Jamal Abdalla , Abdulrahman Mohamed , Abdulrahman Madkour","doi":"10.1016/j.prostr.2025.06.051","DOIUrl":"10.1016/j.prostr.2025.06.051","url":null,"abstract":"<div><div>High-strength concrete (HSC) demonstrates exceptional performance at room temperature, including high compressive and flexural strengths, coupled with remarkable durability. However, it exhibits poor performance under high temperatures due to its dense microstructure that leads to increased risk of explosive spalling. Studies also showed that HSC has higher degradation in its mechanical properties under elevated temperatures compared to normal-strength concrete. Therefore, synthetic fibers, such as polypropylene (PP) fibers are added to the concrete mix to reduce the extent of spalling and increase its fire resistance. This study aims to investigate the degradation in compressive strength properties of HSC, made of local materials in the UAE, with variable composition of PP fibers and steel fibers. Two mix designs were developed in this study. The first mix had 1% steel fibers only, and the second mix consisted of 1% steel fibers with 0.1% PP fiber. Results showed that specimens with steel fibers only exhibited the highest compressive strength at room temperature with the lowest residual The second mix provided comparable strengths to the first mix and acceptable strength degradation. Thus, it can be concluded that the design of the HSC mix can be utilized with the inclusion of synthetic fibers to enhance its fire resistance whilst maintaining its strength. Finally, material models for the degradation in the compressive strength of HSC are developed for the two mixes, respectively.</div></div>","PeriodicalId":20518,"journal":{"name":"Procedia Structural Integrity","volume":"68 ","pages":"Pages 259-265"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144580776","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}

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Creep Crack Growth Testing and Analysis of Laser Powder Bed Fusion 316L Stainless Steel 激光粉末床熔合316L不锈钢蠕变裂纹扩展试验与分析

Procedia Structural Integrity Pub Date : 2025-01-01 DOI: 10.1016/j.prostr.2025.06.113

Amy Milne , Vignesh Siriam , Catrin M. Davies

{"title":"Creep Crack Growth Testing and Analysis of Laser Powder Bed Fusion 316L Stainless Steel","authors":"Amy Milne , Vignesh Siriam , Catrin M. Davies","doi":"10.1016/j.prostr.2025.06.113","DOIUrl":"10.1016/j.prostr.2025.06.113","url":null,"abstract":"<div><div>Additive manufacturing, specifically laser powder bed fusion, is a novel technique which could become key to manufacturing net-shaped metal components with complex geometries. By manufacturing components in successive layers, restrictions on geometric complexity as well as better material economy, reduced manufacturing variability and a reduced manufacturing footprint could be achieved. The current issues with this technique are that very high residual stresses, variations in microstructure and significant pores can be developed. In this work the creep crack growth (CCG) resistance of LPBF 316LSS has been examined by performing tests on compact tension, C(T), samples. The C(T) samples were manufactured in three orthogonal orientations to understand the anisotropic nature of LPBF. The creep crack paths were examined by interrupting tests at the cusp of sample failure, sectioning and preparing the samples for metallographic analysis. Lack of fusion porosity, which forms along layer boundaries, was found to be the dominant factor in creep crack growth rate behaviour, with samples loaded normal to build layers initiation and growing multiple creep cracks. Due to the atypical CCG behaviour of many of the LPBF samples, classical CCG theory could not be applied to analyse the results. It was concluded that for the cases examined, samples which are loaded perpendicular to the build direction but have the crack growing in the build direction i.e. through the build layers sequentially, have the highest CCG resistance due to the relatively lower stress concentration factor of lack of fusion porosity, despite the higher creep strain rate expected in this orientation compared to loading a sample along the build direction.</div></div>","PeriodicalId":20518,"journal":{"name":"Procedia Structural Integrity","volume":"68 ","pages":"Pages 666-673"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144580808","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