Procedia Structural Integrity最新文献_第2页

Assessment of Kitagawa-Takahashi diagram for Ti-6Al-4V manufactured by DED-LB/CW: Evaluation of the interaction between defects and microstructure d - lb /CW法制备Ti-6Al-4V的Kitagawa-Takahashi图评价：缺陷与微观结构相互作用的评价

Procedia Structural Integrity

Pub Date : 2026-01-01 DOI: 10.1016/j.prostr.2025.12.280

Xabat Orue , Mikel Abasolo , Eduardo Tabares , Iban Quintana

This work presents comprehensive fatigue test results utilizing machined specimens extracted horizontally from Ti-6Al-4V blocks manufactured by Direct Energy Deposition using Laser Beam and Coaxial Wire (DED-LB/CW). The experimental results act as basis to establish defect- and microstructure-based models applying the Kitagawa-Takahashi (K-T) approach and the modifications by El Haddad, Murakami and Chapetti. Three batches manufactured in two different DED-LB/CW systems were considered to achieve a variation in microstructure and micropore sizes. Fractographical analyses were executed to examine the size, location and shape of the crack-initiating features. Due to the parameter optimization carried out, Lack of Fusion (LoF) defects were avoided and only shrinkage and keyhole pores were detected. Fatigue Crack Growth (FCG) tests were performed using Compact Tension (CT) specimens to determine the long and effective crack growth thresholds. Kitagawa-Takahashi, El-Haddad, Murakami and Chapetti models were calculated combining fatigue strength, fractographical analysis, as well as fracture mechanics characteristics, achieving good fit with the experimental results. It can be concluded that the interaction between the defects and the microstructure is not negligible. Hence, an application of defect- and microstructure-based models using simplified pore size parameters such as Murakami’s √area, enable a proper assessment of K-T diagrams for life predictions of Ti-6Al-4V manufactured by DED-LB/CW based on FCG behavior.

这项工作展示了综合的疲劳测试结果，利用激光光束和同轴线直接能量沉积（ed - lb /CW）制造的Ti-6Al-4V块水平提取的加工样品。实验结果为应用Kitagawa-Takahashi （K-T）方法和El Haddad、Murakami和Chapetti的修正建立缺陷和微观结构模型提供了基础。考虑在两种不同的ed - lb /CW系统中生产的三个批次，以实现微观结构和微孔尺寸的变化。进行断口分析以检查裂纹起始特征的大小、位置和形状。由于进行了参数优化，避免了LoF缺陷，只检测到缩孔和锁孔。疲劳裂纹扩展（FCG）试验采用致密拉伸（CT）试样进行，以确定长有效裂纹扩展阈值。结合疲劳强度、断口分析及断裂力学特性计算了Kitagawa-Takahashi、El-Haddad、Murakami和Chapetti模型，与实验结果吻合较好。结果表明，缺陷与微观组织之间的相互作用是不可忽略的。因此，使用简化孔径参数（如Murakami 's√area）的基于缺陷和微观结构的模型的应用，能够对基于FCG行为的d - lb /CW制造的Ti-6Al-4V寿命预测的K-T图进行适当评估。

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引用次数: 0

Influence of manufacturing processes to the fatigue strength of thin steel plates. 制造工艺对薄钢板疲劳强度的影响。

Procedia Structural Integrity

Pub Date : 2026-01-01 DOI: 10.1016/j.prostr.2025.12.296

Vladimír Chmelko , Tomáš Koščo , Miroslava Kučerková , Katarína Jevčáková

Many load-bearing components in transport and construction technology are made of sheet metal. The assessment of the fatigue life of such components has its own specificities. The initiation point of fatigue cracks is often the edges that have been formed by splitting from the original sheet metal. The cutting technology significantly affects the condition and properties of the material, as it introduces residual stresses and strain hardening into the material.

In this paper, three different low carbon steel sheet materials (S355, S500, S700) will be analyzed. Comparison of the results of cyclic tests of the sheet metal specimens and different cutting technologies (punching, laser cutting, sharp edge, rounded edge) as well as analysis of fatigue crack initiation sites is presented.

运输和建筑技术中的许多承重部件都是由金属板制成的。这类部件的疲劳寿命评估有其特殊性。疲劳裂纹的起始点通常是由原始金属板分离而形成的边缘。切削技术会在材料中引入残余应力和应变硬化，从而显著影响材料的状态和性能。本文将分析三种不同的低碳钢薄板材料（S355, S500, S700）。对不同切割工艺（冲孔切割、激光切割、锐边切割、圆边切割）下板料试样的循环试验结果进行了比较，并对疲劳裂纹萌生部位进行了分析。

引用次数: 0

Experimental study of towing configurations for a floating wave energy converter 浮动波能转换器拖曳结构的实验研究

Procedia Structural Integrity

Pub Date : 2026-01-01 DOI: 10.1016/j.prostr.2026.01.062

Julian Pforth (M. Eng.) , Christian Keindorf (Prof. Dr.-Ing.)

The essentiality to increase the use of renewable energy sources is driving research in ocean wave and current energy technologies. This study introduces the development of ‘Aurelia WINO’, a prototype of a floating wave energy converter (WEC), designed at Kiel University of Applied Sciences. The system, based on the principle for a point absorber, was constructed in partnership with the maritime industry. To facilitate safe transport to the designated test location near the FINO 3 research platform in the German North Sea, experimental towing trials were conducted using a 1:20 scale model with equivalent floating characteristics.

The experimental setup involved varying length ratios of the towing lines under different current and wave conditions, conducted in the marine flow lab at the Institute of Naval Architecture and Maritime Technologies. The goal was to identify a stable towing configuration that minimizes rolling and tilting. Results from trials indicated that a line ratio of 1.05 yielded the smallest mean tilt and roll angles, especially at current velocities up to 0.2 m/s. Numerical models and analytical calculations supported these experimental findings, demonstrating that the main force on the towing lines was current-induced, with waves contributing additional load.

The study concludes that an adjustable towing configuration with a typical line ratio of 1.05 is optimal for the prototype scale, ensuring minimal tilt and roll angles. This configuration can be adjusted in real-time during transport based on vessel speed, wave height and tidal currents. The integration of numerical, analytical and experimental approaches confirms that analytical calculations suffice for designing towing equipment. However, experimental and numerical analyses are critical for identifying limits on rolling and tilting. This research lays the foundation for scalable towing strategies for full-scale WEC deployment, contributing to the global advancement of marine renewable energy solutions.

增加可再生能源使用的必要性正在推动海浪和当前能源技术的研究。这项研究介绍了“Aurelia WINO”的发展，这是一种浮动波能转换器（WEC）的原型，由基尔应用科学大学设计。该系统基于点吸收器的原理，是与海事行业合作建造的。为了便于安全运输到德国北海FINO 3研究平台附近的指定测试地点，使用具有等效浮动特性的1:20比例模型进行了实验拖曳试验。实验装置包括在不同的水流和波浪条件下拖曳线的不同长度比，在海军建筑和海事技术研究所的海洋流动实验室进行。目标是确定一个稳定的拖曳配置，最大限度地减少滚动和倾斜。试验结果表明，线比为1.05产生的平均倾斜和翻滚角最小，特别是在当前速度高达0.2 m/s的情况下。数值模型和分析计算支持这些实验结果，表明拖曳线上的主要力量是由电流引起的，波浪会产生额外的载荷。研究得出结论，典型线比为1.05的可调拖曳配置最适合原型规模，可确保最小的倾斜和侧滚角。这种配置可以在运输过程中根据船速、浪高和潮流实时调整。数值方法、分析方法和实验方法的结合证实了分析计算对拖曳设备的设计是足够的。然而，实验和数值分析对于确定滚动和倾斜的极限是至关重要的。该研究为全面部署WEC的可扩展拖曳策略奠定了基础，为全球海洋可再生能源解决方案的发展做出了贡献。

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引用次数: 0

Influence of Damping Solutions on the Dynamic Response of Freight Wagons 阻尼解对货车动力响应的影响

Procedia Structural Integrity

Pub Date : 2026-01-01 DOI: 10.1016/j.prostr.2026.01.070

Job S. Silva , Carolina Francisco , Alexandre M. Low , Daniel Jesus , Christian J. Silva , Tiago M.R.M. Domingues , P.M.G.P. Moreira , Paulo Alves , Paulo Oliveira , João Martins , José Rebola , Diogo Alexandre , Ana Amorim , Pedro Marques

Structures subjected to random excitations require efficient vibration control to ensure safety and operational performance. This is particularly relevant for freight wagons, where heavy loads and demanding service conditions call for robust yet cost-effective suspension systems. Traditionally, dry friction damping has been the preferred solution due to its simplicity and durability. However, recent studies have proposed alternative approaches, such as viscoelastic and viscous damping, to enhance vibration attenuation and consistency over time.

In this work, the dynamic response of a reduced-scaled freight wagon model is investigated using a combined experimental–numerical framework. Natural frequencies were identified experimentally using both direct peak-picking on the experimental Power Spectral Densities (PSD) and Stochastic Subspace Identification (SSI) methods, while a finite element (FE) model was developed to replicate the observed modal behavior. The comparison between experimental and numerical results demonstrated good agreement, confirming the validity of the model. These findings establish a foundation for future assessment of damping strategies, including dry friction and viscoelastic systems, for improved freight wagon design.

受到随机激励的结构需要有效的振动控制，以确保安全和运行性能。这尤其适用于货车，重载和苛刻的服务条件需要坚固而经济高效的悬挂系统。传统上，干摩擦阻尼一直是首选的解决方案，因为它简单耐用。然而，最近的研究提出了其他方法，如粘弹性和粘性阻尼，以增强振动衰减和随时间的一致性。本文采用实验-数值相结合的方法研究了一种缩小尺寸的货车模型的动力响应。利用功率谱密度（PSD）和随机子空间识别（SSI）方法对固有频率进行了直接选峰，并建立了一个有限元模型来复制所观察到的模态行为。实验结果与数值结果吻合较好，验证了模型的有效性。这些发现为未来的阻尼策略评估奠定了基础，包括干摩擦和粘弹性系统，以改进货车设计。

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引用次数: 0

Structural Analyses of GFRP with Embedded Fibre Optics Manufactured using Standard and Additive Manufacturing Methods 采用标准和增材制造方法制造的嵌入式光纤玻璃钢的结构分析

Procedia Structural Integrity

Pub Date : 2026-01-01 DOI: 10.1016/j.prostr.2026.01.034

Magdalena Mieloszyk , Suvam Bhadra

This paper aims to analyse the structural differences between glass fibre reinforced polymer (GFRP) with embedded fibre optic sensors, in relation to the manufacturing method. Two methods were analysed: standard infusion and additive manufacturing (AM). For the AM method, a modified fused deposition modelling (FDM) technique was selected.

Structural analyses were performed using a Scanning Electron Microscopy (SEM) and a THz spectrometer. The results showed that the impact of embedded fibre optics on the internal structure of the composite depends on the manufacturing method. In the standard method, the embedded fibres are surrounded by a larger amount of polymer (referred to as a ”resin pocket”), while in the AM structure, part of the next 3D-printed layer shifts over the embedded fibre.

The samples were divided into two sets: one remained intact, while the other was exposed to elevated temperature and tensile loading. The structural integrity of the samples from both sets was assessed using SEM and the THz spectrometer. It was observed that the temperature affected the polymer matrix (resulting in matrix cracking) and the quality of the fibre/matrix interface (with fibres being pulled out). These analyses provided a deeper understanding of the degradation processes in GFRP under mechanical and environmental loading.

本文旨在分析嵌入光纤传感器的玻璃纤维增强聚合物（GFRP）在制造方法上的结构差异。分析了标准注射和增材制造两种方法。对于AM方法，选择了一种改进的熔融沉积建模（FDM）技术。结构分析采用扫描电子显微镜（SEM）和太赫兹光谱仪进行。结果表明，嵌入光纤对复合材料内部结构的影响取决于制造方法。在标准方法中，嵌入的纤维被大量的聚合物（称为“树脂袋”）包围，而在AM结构中，下一个3d打印层的一部分在嵌入的纤维上移动。这些样品被分成两组：一组保持完整，而另一组则暴露在高温和拉伸载荷下。利用扫描电镜和太赫兹光谱仪对两组样品的结构完整性进行了评估。观察到温度影响了聚合物基体（导致基体开裂）和纤维/基体界面的质量（纤维被拉出）。这些分析为GFRP在机械和环境载荷下的降解过程提供了更深入的理解。

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引用次数: 0

Service load analyses for fatigue life calculations and laboratory tests of welded joints of trolleybus bodyworks 无轨电车车体焊接接头疲劳寿命计算及室内试验的使用载荷分析

Procedia Structural Integrity

Pub Date : 2026-01-01 DOI: 10.1016/j.prostr.2026.01.036

Miloslav Kepka , Miloslav Kepka jr. , Radovan Minich , Jaroslav Vaclavik

The operation of city buses, trolleybuses and battery buses on uneven roads causes dynamic and variable amplitude loading of these road vehicles. Such loading can lead to fatigue damage to critical nodes of the bodywork or other vehicle components. Stress-time histories are most often random processes. Such loading processes can be determined by measurement. Fatigue analysis of these processes is fundamentally different from dynamic analysis. Dynamic analyses are performed in the frequency domain. Fatigue analyses must be performed in the time domain to determine the so-called load spectra (histograms of load cycles). Fatigue damage can then be estimated using an appropriate fatigue damage accumulation hypothesis. The contribution presents the results of extensive measurements on several vehicles and in various operating conditions. The so-called design stress spectra for bodywork dimensioning and load spectra for laboratory tests of their critical structural nodes are derived.

城市公交车、无轨电车和纯电动公交车在凹凸不平的路面上行驶，使这些道路车辆产生动态和变幅载荷。这样的载荷会导致车身或其他车辆部件的关键节点的疲劳损伤。压力-时间历史通常是随机过程。这种加载过程可以通过测量来确定。这些过程的疲劳分析与动态分析有本质的不同。在频域中进行动态分析。疲劳分析必须在时域内进行，以确定所谓的载荷谱（载荷周期的直方图）。然后可以使用适当的疲劳损伤累积假设来估计疲劳损伤。该贡献介绍了在几种车辆和各种操作条件下的广泛测量结果。导出了车身尺寸的设计应力谱和关键结构节点的实验室试验载荷谱。

引用次数: 0

Internal swelling reactions in new and existing concrete structures 新建和现有混凝土结构的内部膨胀反应

Procedia Structural Integrity

Pub Date : 2026-01-01 DOI: 10.1016/j.prostr.2026.01.057

João Custódio , Sofia Real , António Bettencourt Ribeiro

Alkali–silica reaction (ASR) and delayed ettringite formation (DEF) in concrete are major durability problems, resulting in significant maintenance and reconstruction costs for concrete infrastructures worldwide. The structures affected by this pathology are important economically and strategically since they are usually encountered in large dams, bridges, and viaducts. This type of degradation is associated with the formation of expansive products within the concrete, causing premature deterioration due to expansion and cracking. This process accelerates the ingress of moisture and other aggressive agents into the concrete, leading to further degradation of the structure. Thus, these swelling reactions can decrease the structure’s service life and, ultimately, lead to its decommissioning or demolition. During the 1920s and 1930s, several concrete structures in California, USA, were observed to develop severe cracking within a few years of their construction. In 1940, Stanton was able to demonstrate that this cracking was related to the existence of an alkali-aggregate reaction. In Portugal, the first cases were detected in the 1980s (Pracana dam and Alto Ceira dam) and 1990s (Duarte Pacheco viaduct). DEF is relatively "new" with respect to ASR, since it was only detected in the middle of the 1980s in pre-stressed concrete railway ties on the eastern coast of the United States. The occurrence of DEF in Portugal is much more recent, with the first case detected only in 2003 in prefabricated concrete railway ties. Despite decades of study, the complex reaction mechanisms of ASR and DEF have resulted in the inability to assess the risk efficiently, predict the service life, and mitigate deterioration in susceptible structures. Because of that, the problem was not eradicated, and today, numerous concrete structures still exhibit ASR and DEF. This paper offers a concise overview of managing these phenomena in both new and existing structures, emphasising reaction mechanisms, factors influencing their development, their impact on concrete, prevention in new structures, and mitigation in existing ones.

混凝土中的碱-硅反应（ASR）和延迟钙矾石形成（DEF）是主要的耐久性问题，导致世界范围内混凝土基础设施的重大维护和重建成本。受这种疾病影响的结构在经济上和战略上都很重要，因为它们通常在大型水坝、桥梁和高架桥中遇到。这种类型的退化与混凝土内部膨胀产物的形成有关，由于膨胀和开裂而导致过早劣化。这一过程加速了水分和其他侵蚀剂进入混凝土，导致结构进一步退化。因此，这些膨胀反应会降低结构的使用寿命，并最终导致其退役或拆除。在20世纪20年代和30年代，美国加利福尼亚州的几个混凝土结构在建造的几年内就出现了严重的裂缝。1940年，斯坦顿证明了这种开裂与碱-骨料反应的存在有关。在葡萄牙，第一批病例是在20世纪80年代（普拉卡纳大坝和阿尔托塞拉大坝）和90年代（杜阿尔特帕切科高架桥）发现的。就ASR而言，DEF是相对“新的”，因为它只是在20世纪80年代中期在美国东海岸的预应力混凝土铁路绑带中发现的。DEF在葡萄牙的发生要晚得多，仅在2003年在预制混凝土铁路连接中发现了第一例病例。尽管经过数十年的研究，但由于ASR和DEF的复杂反应机制，导致无法有效评估风险、预测使用寿命和减轻易感结构的恶化。正因为如此，问题并没有根除，今天，许多混凝土结构仍然表现出ASR和DEF。本文简要概述了在新结构和现有结构中管理这些现象，强调反应机制，影响其发展的因素，它们对混凝土的影响，新结构的预防和现有结构的缓解。

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引用次数: 0

Hydrogen Embrittlement and Fracture Behavior of Aged Pipeline Steels: Challenges for Hydrogen Transport in Gas Infrastructure 老化管道钢的氢脆及断裂行为：天然气基础设施中氢气输送的挑战

Procedia Structural Integrity

Pub Date : 2026-01-01 DOI: 10.1016/j.prostr.2026.01.061

Olha Zvirko

The hydrogen economy continues to develop, with persistent technical barriers in pipeline infrastructure hindering large-scale hydrogen transportation. The repurposing of natural gas pipeline network for hydrogen transport offers a strategic pathway for decarbonizing energy systems. However, material compatibility challenges persist, particularly hydrogen embrittlement in aged infrastructure. This study evaluates hydrogen embrittlement susceptibility in pipeline steels considering two states: as-received and post-operated (after long-term service). Mechanical testing and fractographic analysis, combined with electrolytic hydrogen charging, reveal critical dependencies on material condition and hydrogen exposure. Post-operated steel exhibited pronounced hydrogen embrittlement sensitivity, with higher fracture toughness reductions under hydrogen charging, compared to as-received specimens. A displacement rate dependence was identified, where lower rates reduced fracture toughness compared to quasi-static conditions. These findings provide critical insights for safe gas pipeline repurposing, addressing both technical and strategic dimensions of the hydrogen economy.

氢经济持续发展，但管道基础设施的技术壁垒持续存在，阻碍了大规模的氢运输。天然气输氢管网的改造为能源系统脱碳提供了一条战略途径。然而，材料相容性的挑战仍然存在，特别是在老化的基础设施中氢脆。本研究评估了管道钢的氢脆敏感性，考虑了两种状态：接收状态和运行后（长期使用后）。力学测试和断口分析，结合电解氢气充电，揭示了材料条件和氢气暴露的关键依赖关系。术后钢表现出明显的氢脆敏感性，与接收的试样相比，在充氢下具有更高的断裂韧性降低。研究发现，与准静态条件相比，较低的排量会降低断裂韧性。这些发现为安全天然气管道的重新利用提供了重要的见解，解决了氢经济的技术和战略层面。

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引用次数: 0

Optimization of 3D printing parameters to minimize residual stresses in maraging steel 优化3D打印参数以最小化马氏体时效钢的残余应力

Procedia Structural Integrity

Pub Date : 2026-01-01 DOI: 10.1016/j.prostr.2026.01.067

Karel Trojan , Ivana Zetková , Jiří Čapek , Tomáš Bakša , Kateřina Aubrechtová Dragounová , Nikolaj Ganev , Miloslav Kepka jr. , Luboš Rozkošný

Fatigue crack initiation and propagation are critical in determining fatigue life, as they are significantly affected by surface roughness, microstructural parameters (such as dislocation density, crystallite size, and microcracks), and especially by macroscopic residual stresses. During additive manufacturing via selective laser melting, a complex distribution of residual stresses is introduced, which can substantially affect both the printing process and the mechanical behaviour of the final component. In some cases, the magnitude of these stresses can approach the yield strength of the material. Consequently, research has focused on optimizing 3D printing parameters to minimize RS in maraging steel. The macroscopic residual stress profile, obtained through X-ray diffraction combined with gradual electrolytic removal of surface layers, was analysed and compared with mechanical properties, particularly fatigue life. Samples were subjected to high cycle fatigue testing to investigate the influence of various factors on fatigue performance. It has been demonstrated that fatigue life is influenced not only by residual stresses at the surface but also by those present in the near-surface layers, highlighting the importance of stress distribution in fatigue performance.

疲劳裂纹的萌生和扩展是决定疲劳寿命的关键因素，因为它们受到表面粗糙度、微观结构参数（如位错密度、晶粒尺寸和微裂纹），尤其是宏观残余应力的显著影响。在通过选择性激光熔化的增材制造过程中，引入了复杂的残余应力分布，这可以极大地影响打印过程和最终组件的机械行为。在某些情况下，这些应力的大小可以接近材料的屈服强度。因此，研究的重点是优化3D打印参数，以最大限度地减少马氏体时效钢中的RS。通过x射线衍射结合逐渐电解去除表面层得到宏观残余应力分布图，分析并比较了其力学性能，特别是疲劳寿命。对试样进行了高周疲劳试验，研究了各种因素对试样疲劳性能的影响。研究表明，疲劳寿命不仅受到表面残余应力的影响，而且受到近表层残余应力的影响，这突出了应力分布在疲劳性能中的重要性。

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引用次数: 0

Effect of time on longitudinal fracture in functionally graded beam constructions 时间对功能梯度梁结构纵向断裂的影响

Procedia Structural Integrity

Pub Date : 2026-01-01 DOI: 10.1016/j.prostr.2026.01.049

Victor Rizov

The present paper studies theoretically how the longitudinal fracture in functionally graded beam constructions is affected by the time. The beam explored has non-linear viscoelastic mechanical behaviour under static loading. Furthermore, the beam is functionally graded in the direction of thickness. To treat the viscoelastic deformation of the structure, a theoretical model representing a combination of linear and nonlinear dampers and springs is applied. This model has two parameters, namely the modulus of elasticity of the non-linear spring and the coefficient of viscosity of the non-linear dashpot which change with time. The time-dependent strain energy release rate is derived. A significant influence of the time factor on the strain energy release rate is detected. For example, it is found that the strain energy release rate – time graph has an upward slop. The question of the influence of the elastic modulus and the viscosity coefficient on the time-dependent behavior of the strain energy release rate is also clarified.

本文从理论上研究了时间对功能梯度梁结构纵向断裂的影响。所研究的梁在静载荷作用下具有非线性粘弹性力学行为。此外，梁在厚度方向上具有功能梯度。为了处理结构的粘弹性变形，采用了线性和非线性阻尼器和弹簧组合的理论模型。该模型有两个参数，即非线性弹簧的弹性模量和非线性阻尼器的粘滞系数，它们随时间变化。导出了随时间变化的应变能释放率。时间因素对应变能释放率有显著影响。例如，发现应变能释放率-时间曲线有一个向上的斜率。阐明了弹性模量和粘滞系数对应变能释放率随时间变化的影响问题。

引用次数: 0