Experimental Mechanics最新文献_第5页

Synergistic Effects of Foam Reinforcement and Geometric Parameters on the Mechanics of Re-Entrant Auxetic Structures 泡沫配筋与几何参数对再入式结构力学的协同效应

IF 2.4 3区工程技术 Q2 MATERIALS SCIENCE, CHARACTERIZATION & TESTING

Experimental Mechanics

Pub Date : 2025-06-11 DOI: 10.1007/s11340-025-01205-x

E. Kucukkalfa, B. Yilmaz, K. Yildiz

Background

Enhancing the energy absorption capacity and strength-to-weight ratio of engineering structures under compression and impact loads is crucial. Auxetic lattice structures, which feature a negative Poisson’s ratio, offer enhanced energy absorption through their geometric designs that cause inward clustering rather than outward expansion under compression, yet typically suffer from low stiffness and load-carrying capacity.

Objective

Rigid polymeric foam reinforcement within the unit cells can substantially improve their mechanical properties, including compressive stiffness and energy absorption. This study examines how polyurethane (PU) foam reinforcement affects re-entrant auxetic lattice structures, considering variations in cell wall thickness and unit cell numbers.

Methods

Utilizing three distinct cell wall thicknesses and three different unit cell numbers while maintaining the overall geometry constant, PU foams are synthesized directly within the unit cells to study the mechanical properties under compression tests.

Results

Comprehensive analyses reveal that both cell wall thickness and unit cell numbers significantly enhance mechanical performance, along with the integration of PU foam which dramatically amplifies energy absorption related properties. Additional data-driven modeling revealed that stiffness and strength are predominantly governed by the number of unit cells, while foam reinforcement enhances energy absorption, validating the deformation mechanisms observed during mechanical testing. Among the configurations tested, the sample with the thickest cell walls and the highest number of unit cells, reinforced with directly synthesized polyurethane foam, demonstrated the most significant improvement, achieving a specific energy absorption of 10.211 MJ/kg, which highlights the critical role of optimal foam integration in boosting the mechanical performance of auxetic structures under compressive loads.

Conclusions

The proposed method effectively enhances the mechanical performance of auxetic lattice structures by integrating PU foam reinforcement, significantly improving compressive stiffness and energy absorption capacity.

背景提高工程结构在压缩和冲击载荷作用下的吸能能力和强重比至关重要。辅助晶格结构具有负泊松比，通过其几何设计提供增强的能量吸收，在压缩下导致向内聚集而不是向外膨胀，但通常具有低刚度和承载能力。目的：对单体胞内的刚性聚合物泡沫进行加固，可显著改善其力学性能，包括抗压刚度和能量吸收。本研究考察了聚氨酯（PU）泡沫增强如何影响重新进入的缺陷晶格结构，考虑到细胞壁厚度和单元胞数的变化。方法在保持整体几何常数的情况下，利用三种不同的壁厚和三种不同的单元胞数，在单元胞内直接合成聚氨酯泡沫，研究其压缩力学性能。结果综合分析表明，胞壁厚度和胞胞数量均显著提高了材料的力学性能，同时聚氨酯泡沫的加入显著提高了材料的吸能性能。额外的数据驱动模型显示，刚度和强度主要取决于单元格的数量，而泡沫加固增强了能量吸收，验证了力学测试中观察到的变形机制。在测试的构型中，直接合成聚氨酯泡沫塑料增强的胞壁最厚、胞胞数量最多的样品改善效果最显著，比能吸收达到10.211 MJ/kg，这凸显了优化泡沫塑料整合对提高压缩载荷下减振结构力学性能的关键作用。结论该方法通过集成PU泡沫加固，有效提高了外加点阵结构的力学性能，显著提高了抗压刚度和吸能能力。

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引用次数: 0

Opening-Dominated Fracture Characterization of Single Crystal Spinel in the Transmission Electron Microscope 单晶尖晶石开口主导断口的透射电镜表征

IF 2.4 3区工程技术 Q2 MATERIALS SCIENCE, CHARACTERIZATION & TESTING

Experimental Mechanics

Pub Date : 2025-06-11 DOI: 10.1007/s11340-025-01206-w

Y. Zhang, S.J. Dillon, J. Lambros

Background

Characterizing deformation and failure mechanisms through small-scale testing has helped in the fundamental understanding of material response, and direct loading in a transmission electron microscope (TEM) has played a large role in this effort. However, crystalline materials exhibit incoherent scattering within the TEM and the resulting intensity variations inhibit direct optical metrology.

Objective

In this work, we seek to both validate an in situ optical full-field metrology method in the TEM for use with crystalline materials, and measure fracture properties of a MgAl₂O₄spinel single crystal at the microscale.

Methods

Microscale single edge notch bend beams were machined from a spinel single crystal and loaded in the TEM. In situ imaging of a nanoscale speckle pattern allowed use of particle tracking (PT) to extract full-field measurements of the displacement field. A numerical analysis methodology was then used to obtain mixed mode stress intensity factor values.

Results

A discrepancy between PT and far-field actuator measurements of applied displacement was found (about a maximum of 35% difference), indicating the advantage of using near-field optical measurements in the TEM. For such small-scale testing it is also generally unavoidable to introduce asymmetry in loading. However, the PT results allowed measurement of both K_I and K_II, which were found to be at the time of crack initiation K_IC = 1.51± 0.03 MPa∙m^0.5, K_IIC = 0.04± 0.002 MPa∙m^0.5, respectively.

Conclusions

The application of PT enables full-field deformation measurements on crystalline materials deformed in the TEM. The effectiveness of the inverse property extraction was demonstrated by good agreement between the full-field PT measurements and FEM results. The MgAl₂O₄ spinel toughness values extracted also agreed well with previous literature results.

通过小规模试验表征变形和破坏机制有助于对材料响应的基本理解，而透射电子显微镜（TEM）的直接加载在这一努力中发挥了重要作用。然而，晶体材料在TEM中表现出非相干散射，由此产生的强度变化抑制了直接光学测量。目的在本工作中，我们试图在TEM中验证用于晶体材料的原位光学全场计量方法，并在微观尺度上测量mgal2o4尖晶石单晶的断裂性能。方法将尖晶石单晶加工成微尺度单边缘缺口弯曲梁，并在透射电镜下加载。纳米尺度散斑模式的原位成像允许使用粒子跟踪（PT）来提取位移场的全场测量。然后采用数值分析方法获得混合模态应力强度因子值。结果PT与远场致动器测量的外加位移存在差异（最大差异约35%），表明在TEM中使用近场光学测量具有优势。对于这样的小规模试验，通常也不可避免地引入不对称加载。然而，PT结果允许同时测量KI和KII，发现在裂纹起裂时KIC = 1.51±0.03 MPa∙m0.5, KIIC = 0.04±0.002 MPa∙m0.5。结论PT的应用可以实现晶体材料在TEM中变形的全场变形测量。现场PT测量结果与有限元分析结果吻合较好，证明了反性质提取的有效性。提取的MgAl2O4尖晶石韧性值与文献结果吻合较好。

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引用次数: 0

Experiments and Computational Modeling of a Sealed Open Cell Foam in an Underwater Shock Tube 水下激波管内密封开孔泡沫的实验与计算模型

IF 2.4 3区工程技术 Q2 MATERIALS SCIENCE, CHARACTERIZATION & TESTING

Experimental Mechanics

Pub Date : 2025-06-02 DOI: 10.1007/s11340-025-01194-x

E. L. Guzas, B. M. Casper, M. A. Babina, I. N. Chenwi, A. Shukla

Background

Open cell foams have recently been used as a simulant for lung parenchyma to model underwater blast injury and thus the foam’s mechanical response characteristics are of interest to the underwater blast community.

Objective

The compressive response of a soft, sealed open cell foam (FlexFoam-iT! VIII) subjected to underwater hydrostatic pressure and shock is investigated through an experimental and computational study.

Methods

Real-time deformation of the foam during loading is captured via high-speed cameras, and a 3D digital image correlation technique calculates the foam’s transient volumetric strain. Fully coupled fluid–structure interaction (FSI) models of the experiments are developed for the FSI code Dynamic System Mechanics Advanced Simulation (DYSMAS), where the Arruda-Boyce hyperelastic model calculates the foam constitutive behavior.

Results

Simulated foam volumetric strains exhibit excellent correlation to shock test data. Hydrostatic experiments show that deformation of the sealed foam under hydrostatic compression is similar to the behavior of compressed air, until reaching volumetric strain levels exceeding 50%. Quasistatic DYSMAS simulations at numerous applied hydrostatic pressures produce volumetric strains between those measured in hydrostatic experiments with sealed foam (lower bound of strain at a given pressure) and in confined compression experiments with unsealed foam (upper bound).

Conclusion

The FSI modeling approach in DYSMAS showed a strong correlation with experimental results. Given this foam's prior successful use in a physical lung simulant, this computational approach is a good candidate for future modeling of human lung tissue response to underwater shock.

最近，开孔泡沫被用作肺实质模拟物来模拟水下爆炸损伤，因此泡沫的力学响应特性引起了水下爆炸界的兴趣。目的研究柔性密封开孔泡沫塑料(FlexFoam-iT！通过实验和计算研究了水下静水压力和冲击作用。方法通过高速摄像机捕捉泡沫在加载过程中的实时变形，并利用三维数字图像相关技术计算泡沫的瞬态体积应变。基于FSI程序动态系统力学高级模拟（DYSMAS），建立了全耦合流固耦合（FSI）实验模型，其中Arruda-Boyce超弹性模型计算了泡沫的本构行为。结果模拟泡沫体应变与冲击试验数据具有良好的相关性。静水实验表明，密封泡沫在静水压缩下的变形与压缩空气的行为相似，直到达到超过50%的体积应变水平。在许多应用静水压力下的准静态DYSMAS模拟产生的体积应变介于密封泡沫静水实验（给定压力下应变的下界）和非密封泡沫密闭压缩实验（上界）中测量的体积应变之间。结论FSI建模方法与实验结果具有较强的相关性。考虑到这种泡沫之前在物理肺部模拟中的成功应用，这种计算方法是未来模拟人体肺组织对水下冲击反应的一个很好的选择。

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引用次数: 0

Exploring Humerus Bone’s Fracture Patterns and Fixation Systems Via Laser Vibrometry 用激光振动仪研究肱骨骨折模式和固定系统

IF 2.4 3区工程技术 Q2 MATERIALS SCIENCE, CHARACTERIZATION & TESTING

Experimental Mechanics

Pub Date : 2025-06-02 DOI: 10.1007/s11340-025-01198-7

B. Carboni, S. K. Guruva, S. Gumina, V. Candela, J. Tirilló, C. Sergi, T. Valente, W. Lacarbonara

Background

The mechanical performance assessment of orthopedic fixation systems is computationally and experimentally challenging due to the complex geometrical and mechanical features of bones. Non-contact experimental techniques, widely adopted in several engineering fields, is shown to overcome these issues.

Objective

This work discusses a comparative experimental investigation into specimens mimicking healthy humerus bones and fractured bones subject to an innovative surgery procedure and to a classical technique referred to as the gold standard surgery. The new surgery consists in the installation of an external fixation mechanism that constrains, according to different spatial patterns, a certain number of titanium slender bars inserted and clamped into the fractured bones.

Methods

The mechanical properties of artificial bones are characterized through compressive tests, while the morphology of the fracture surface is analyzed using a scanning electron microscope. A three-dimensional laser vibrometer is used to measure the resonance frequencies, mode shapes, damping ratios, and mechanical waves propagating from the actuators across the surface of the bones.

Results

The results provide insights into which configuration of the fixator performs better for a fast recovery. Based on the observed dynamic behaviors, the optimal configuration of the fixator offers performance that is comparable to, or potentially better than, the gold standard surgical procedure.

Conclusions

The novelty and feasibility of the adopted experimental approach paves the way towards the adoption of advanced non-contact techniques for the mechanical characterization of complex, non-homegenous and anisotropic materials and structures in biomedical applications enabling also data-driven models of the systems.

由于骨骼复杂的几何和力学特征，骨科固定系统的力学性能评估在计算和实验上都具有挑战性。非接触式实验技术被广泛应用于多个工程领域，克服了这些问题。目的本研究讨论了一项比较实验研究，通过一种创新的手术程序和一种被称为金标准手术的经典技术来模拟健康的肱骨和骨折的骨头。新的手术包括安装一个外固定装置，根据不同的空间模式，将一定数量的钛细长棒插入并夹入骨折的骨头中。方法通过压缩试验对人工骨的力学性能进行表征，同时用扫描电镜对断口形貌进行分析。三维激光测振仪用于测量谐振频率、模态振型、阻尼比和从驱动器穿过骨骼表面传播的机械波。结果说明了哪种固定架配置对快速恢复效果更好。根据观察到的动态行为，固定架的最佳配置提供了与金标准手术程序相当或可能更好的性能。所采用的实验方法的新颖性和可行性为采用先进的非接触技术来表征生物医学应用中复杂、非均质和各向异性材料和结构的力学特性铺平了道路，也使系统的数据驱动模型成为可能。

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引用次数: 0

On the Cover: Overcoming Dynamic Stiffness Damping Trade Off with Structural Gradients in 3D Printed Elastomeric Gyroid Lattices 封面：克服动态刚度阻尼权衡与结构梯度在3D打印弹性体陀螺晶格

IF 2.4 3区工程技术 Q2 MATERIALS SCIENCE, CHARACTERIZATION & TESTING

Experimental Mechanics

Pub Date : 2025-06-02 DOI: 10.1007/s11340-025-01202-0

引用次数: 0

A Novel MEMS Platform for Thermomechanical Characterization of Nanomaterials 纳米材料热力学表征的新型MEMS平台

IF 2.4 3区工程技术 Q2 MATERIALS SCIENCE, CHARACTERIZATION & TESTING

Experimental Mechanics

Pub Date : 2025-06-02 DOI: 10.1007/s11340-025-01199-6

D. Kundu, B. Zhang, Z. Lin, G. Richter, H. D. Espinosa

Background

Thermomechanical testing of nanomaterials is essential to assess their performance in applications where thermal and mechanical loads occur simultaneously. However, developing a multi-physics testing platform for nanomaterials that integrates temperature control, displacement control, and force sensing remains challenging due to the interference between heating and mechanical testing components.

Objective

This work aims to develop a novel microelectromechanical system-based platform for in situ thermomechanical testing of nanomaterials with displacement control and precise temperature regulation.

Methods

The platform integrates a high-stiffness thermal actuator, Joule heating elements, and a capacitive displacement sensor, along with sample stage heaters featuring thermal insulation and thermal expansion compensation structures. Finite element analysis was used to optimize the design and minimize thermomechanical interference. Heating performance was characterized using Raman spectroscopy and resistance measurements.

Results

Displacement control and precise localized temperature control are achieved, overcoming limitations of transient heat transfer and thermal drift observed in previous systems. Its performance is demonstrated through in situ thermomechanical tensile testing of silver nanowires, showcasing its capability for nanoscale material characterization.

Conclusions

The developed microelectromechanical system platform enables thermomechanical investigation of size-dependent phenomena in nanomaterials, such as phase transitions and temperature-dependent fracture. Its displacement control and localized temperature regulation, combined with in-situ observation, provide a powerful tool for understanding nanoscale deformation and fracture mechanisms.

纳米材料的热力学测试对于评估其在热载荷和机械载荷同时发生的应用中的性能至关重要。然而，由于加热和机械测试组件之间的干扰，开发一个集成温度控制、位移控制和力传感的纳米材料多物理场测试平台仍然具有挑战性。目的建立基于微机电系统的纳米材料原位热力学测试平台，实现纳米材料的位移控制和精确温度调节。方法该平台集成了高刚度热致动器、焦耳加热元件和电容位移传感器，以及具有隔热和热膨胀补偿结构的样品台加热器。采用有限元分析优化设计，最大限度地减少热机械干扰。利用拉曼光谱和电阻测量对加热性能进行了表征。结果实现了位移控制和精确的局部温度控制，克服了以往系统的瞬态传热和热漂移的局限性。通过银纳米线的原位热力学拉伸测试证明了其性能，展示了其纳米级材料表征的能力。结论所开发的微机电系统平台能够对纳米材料的尺寸相关现象进行热力学研究，如相变和温度相关断裂。它的位移控制和局部温度调节，结合现场观测，为理解纳米尺度的变形和破裂机制提供了有力的工具。

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引用次数: 0

Digital Holographic Moiré Generalized NanoFraction 数字全息摄影：广义纳米分数

IF 2.4 3区工程技术 Q2 MATERIALS SCIENCE, CHARACTERIZATION & TESTING

Experimental Mechanics

Pub Date : 2025-05-30 DOI: 10.1007/s11340-025-01195-w

C.A. Sciammarella, L. Lamberti, E. Sciammarella, F.M. Sciammarella, L. Santoro

Background

Nanoscale investigations with ordinary optical microscopes require evanescent fields resolution when the target is to go beyond the λ/2 resolution limit. Photon-phonon interactions from quantum mechanics to Newtonian mechanics, explain how traditional microscopy can achieve nanometric accuracy in Experimental Mechanics.

Objectives

To detail NanoFraction (NF), a digital system that works beyond the limits of traditional optical microscopy.

Methods

The NF system is an extension of more than two decades of research work by the authors in super-resolution. NF overcomes the λ/2 resolution limit by recording the near-field in the far-field, enabling broader fields of view with unmatched spatial resolution. NF uses lasers with wavelengths between 400 and 700 nm to capture images of objects in the nanometer range. Unlike fluorescent super-resolution or cryogenic electron microscopy, NF is a label-free imaging modality. Artificial intelligence (AI) is integral to the NF system.

Results

The NF system is successfully utilized for nanoscale investigations in chemistry, semi-conductor industry and living organisms such as (i) detection of crystalline structures (i.e. NaCl nano-crystals); (ii) detection of defects in diamond wafers; (iii) detection of COVID-19 virus structures. The article demonstrates how the NF system can be applied to organic materials, such as the COVID-19 virus.

Conclusions

NF allows to visualize details that were previously only visible with transmission electron microscopy (TEM), but without the limitations of this technique. The NF system has important implications for understanding the nanoworld.

在普通光学显微镜下进行纳米尺度的研究，当目标要超过λ/2分辨率极限时，就需要瞬变场分辨率。从量子力学到牛顿力学的光子-声子相互作用，解释了传统显微镜如何在实验力学中实现纳米级精度。目的详细介绍纳米分数（NF），一种超越传统光学显微镜限制的数字系统。方法NF系统是作者在超分辨率方面二十多年研究工作的延伸。NF通过在远场记录近场，克服了λ/2分辨率的限制，实现了更广阔的视野和无与伦比的空间分辨率。NF使用波长在400到700纳米之间的激光来捕捉纳米范围内物体的图像。与荧光超分辨率或低温电子显微镜不同，NF是一种无标签的成像方式。人工智能（AI）是NF系统不可或缺的一部分。结果NF系统成功地应用于化学、半导体工业和生物体的纳米尺度研究，如：(1)晶体结构（即NaCl纳米晶体）的检测；（ii）检测金刚石晶圆的缺陷；（三）检测COVID-19病毒结构。本文演示了NF系统如何应用于有机材料，如COVID-19病毒。结论：snf可以使以前只能通过透射电子显微镜（TEM）才能看到的细节可视化，但没有这种技术的局限性。NF系统对于理解纳米世界具有重要意义。

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引用次数: 0

A Method to Perform an Experimental Modal Analysis of a Medium Head Francis Runner in Operation 一种运行中水头混流式转轮试验模态分析方法

IF 2.4 3区工程技术 Q2 MATERIALS SCIENCE, CHARACTERIZATION & TESTING

Experimental Mechanics

Pub Date : 2025-05-28 DOI: 10.1007/s11340-025-01185-y

A. Tessier, M. Coulaud, D. Thibault, S. Houde, Y. St-Amant

Background

Hydraulic turbines are increasingly used outside the range of operation for which they were designed due to the growth of electricity produced by wind and solar power sources, which are intermittent. The new operating ranges cause high level of vibrations that reduce significantly the lifespan of the turbine runner. Modal parameters of the runner are influenced by the operating condition, but the extent of this influence remains unknown. Closely spaced modes, which are typical in turbine runners, also remain challenging to identify.

Objective

This paper presents a methodology for conducting an experimental modal analysis of a medium head model Francis turbine runner during operation, with the objective of identifying its natural frequencies and damping ratios while minimizing the impact on the hydraulic surface.

Methods

The runner of a medium head model Francis turbine is instrumented with piezoelectric actuators located on the outer side of the band and semiconductor strain gauges on the blades and the inner side of the band. Classical strain gauges and accelerometers are installed as reference measurements. Piezoelectric actuators are driven by sine sweep signals to generate standing and travelling waves matching the mode shapes of band dominant modes. Natural frequencies and damping ratios are then identified from the frequency response functions.

Results

The energy injected by the piezoelectric actuators is sufficiently high to excite band-dominant natural modes of the runner in operation. The high sensitivity of semiconductor strain gauges allows for low-noise measurements compared to classical strain gauges. The quality of the obtained frequency response functions is high, enabling the identification of natural frequencies and damping ratios and resulting in strong agreement between measured and model-predicted responses. With eight piezoelectric actuators located on the band, the use of traveling wave excitation pattern allows for the individual excitation of the forward and backward components of the first two pairs of band-dominant natural modes.

Conclusion

The proposed method for conducting experimental modal analysis enables the identification of modal parameters of a model Francis turbine runner in operation. By using a traveling wave excitation pattern, the method allows for the individual excitation of the forward and backward components of band-dominant natural modes—provided the number of actuators is sufficiently large—which is particularly beneficial for identifying closely spaced modes when such modes are present.

水力涡轮机越来越多地在其设计的运行范围之外使用，这是由于风能和太阳能发电的增长，这是间歇性的。新的操作范围引起高水平的振动，大大减少了涡轮转轮的寿命。转轮的模态参数受工况的影响，但影响的程度尚不清楚。紧密间隔模式，这是典型的涡轮转轮，也仍然具有挑战性的识别。本文提出了一种对中型水头型混流式水轮机转轮在运行过程中进行试验模态分析的方法，目的是确定其固有频率和阻尼比，同时最大限度地减少对液压表面的影响。方法在中水头型混流式水轮机转轮的传动带外侧安装了压电作动器，叶片和传动带内侧安装了半导体应变片。安装经典应变计和加速度计作为参考测量。压电驱动器由正弦扫描信号驱动，产生与带优势模态振型相匹配的驻波和行波。然后从频率响应函数中确定固有频率和阻尼比。结果压电致动器注入的能量足够高，可以激发转轮运行时的带状优势自然模态。与经典应变片相比，半导体应变片的高灵敏度允许进行低噪声测量。所获得的频率响应函数的质量很高，能够识别固有频率和阻尼比，并在测量和模型预测响应之间产生强烈的一致性。带上有八个压电致动器，使用行波激励模式可以单独激励前两对带主导自然模态的前向和后向分量。结论本文提出的试验模态分析方法能够识别运行中的水轮机混流式转轮模型模态参数。通过使用行波激励模式，该方法允许单独激励带优势自然模式的前向和后向分量——只要执行器的数量足够大——当这种模式存在时，这对识别紧密间隔的模式特别有益。

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引用次数: 0

Effects of Drilling Induced Heating During IHD of FRP Laminates 钻致加热对玻璃钢层合板IHD的影响

IF 2.4 3区工程技术 Q2 MATERIALS SCIENCE, CHARACTERIZATION & TESTING

Experimental Mechanics

Pub Date : 2025-05-22 DOI: 10.1007/s11340-025-01196-9

M. Horan, T. C. Smit, R.G. Reid

Background

Incremental hole-drilling has been used extensively in composite laminates, however, the low thermal conductivity of GFRP laminates results in drilling induced heat build-up near the hole. This can lead to measurement errors due to post-cure shrinkage of the matrix, and additional thermal drift errors arising from the necessary data acquisition delay after each drilling increment to allow adequate heat dissipation before taking strain measurements.

Objective

Investigate the significance of drilling induced post-cure shrinkage and the effects of different bottom-surface thermal boundary conditions on the drilling induced heat dissipation in GFRP laminates during IHD.

Methods

IHD is performed on GFRP laminates, specifically an annealed ([0_{8}]) laminate and a ([0_{2}/90_{2}]_{s}) laminate with different support configurations. The through-thickness residual stress distribution is determined using the integral computational method. The magnitude of drilling induced post-cure shrinkage effects and those of the different thermal boundary conditions are investigated.

Results

IHD on the annealed ([0_{8}]) specimens demonstrated that drilling induced post-cure shrinkage effects are not significant. The use of different thermal boundary conditions for the ([0_{2}/90_{2}]_{s}) specimens demonstrated the necessity for good heat transfer out of the laminate to achieve accurate results.

Conclusions

Carefully performed IHD does not cause sufficient drilling induced heating to result in post-cure shrinkage of GFRP laminates. Experimental parameters and the thermal boundary conditions of the bottom surface must be carefully considered to ensure a successful measurement. A lack of good heat transfer out of the bottom surface of the specimen increases the required testing time and can produce unreliable results.

背景：渐进式钻孔已广泛应用于复合材料层压板，然而，GFRP层压板的低导热性导致钻孔引起的热积聚在孔附近。这可能会导致由于基体固化后收缩而产生的测量误差，以及由于每次钻井增量后必要的数据采集延迟而产生的额外热漂移误差，以便在进行应变测量之前充分散热。目的探讨钻孔致固化后收缩的意义，以及不同底表面热边界条件对GFRP复合材料在IHD过程中钻孔致散热的影响。方法在GFRP层压板上进行sihd，特别是退火([0_{8}])层压板和具有不同支撑配置的([0_{2}/90_{2}]_{s})层压板。采用积分计算法确定了整个厚度的残余应力分布。研究了钻孔引起的固化后收缩效应的大小以及不同热边界条件下的收缩效应。结果对([0_{8}])退火试样进行的hd实验表明，钻孔引起的固化后收缩效应不显著。对([0_{2}/90_{2}]_{s})试样使用不同的热边界条件表明，为了获得准确的结果，层压板必须有良好的传热。结论仔细进行的IHD不会引起足够的钻孔引起的加热导致GFRP层合板的固化后收缩。为了保证测量的成功，必须仔细考虑实验参数和底表面的热边界条件。试样底表面缺乏良好的热传递会增加所需的测试时间，并可能产生不可靠的结果。

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引用次数: 0

Tuning Energy Absorption of Metallic TPMS Cellular Structures via Wall Thickness Gradient Design 基于壁厚梯度设计的金属TPMS细胞结构的能量吸收调谐

IF 2.4 3区工程技术 Q2 MATERIALS SCIENCE, CHARACTERIZATION & TESTING

Experimental Mechanics

Pub Date : 2025-05-15 DOI: 10.1007/s11340-025-01190-1

M. Zhong, W. Zhou, Z. Wu, J. Deng, Y. Du

Background

In the study of laser melting fabricated 316L stainless steel triply periodic minimal surface (TPMS) structures, a knowledge gap persists. The understanding of optimizing deformation mechanisms and energy absorption, especially via gradient wall thickness design, remains inadequate.

Objective

The main aim of this research is to explore the deformation and energy absorption features of particular 316L stainless steel TPMS structures made by laser melting, emphasizing the use of gradient wall thickness design to improve overall energy absorption.

Methods

An integrated experimental and computational approach was developed. TPMS structures with diverse wall thicknesses were fabricated through laser melting. Then, detailed analyses were performed to examine stress and deformation under compression. The novelty was the local strategies in gradient wall thickness design for enhanced stress redistribution.

Results

Quantitatively, compared to uniform ones, the specific energy absorption (SEA) of gradient structures rose by 18.3% along the loading direction and 26.8% perpendicular to diagonal shearing. Qualitatively, the gradient design reduced early densification and improved stress redistribution, yielding new insights for future designs.

Conclusions

Overall, the strategic use of gradient design and wall thickness control significantly boosts the SEA of laser melting fabricated 316L stainless steel TPMS structures, showing great potential for future applications.

在激光熔化制备316L不锈钢三周期最小表面（TPMS）结构的研究中，知识差距仍然存在。对优化变形机制和能量吸收的理解，特别是通过梯度壁厚设计，仍然不足。目的探讨激光熔化316L不锈钢TPMS结构的变形和吸能特性，强调采用梯度壁厚设计来提高整体吸能。方法建立了一种实验与计算相结合的方法。采用激光熔化法制备了不同壁厚的TPMS结构。然后，进行了详细的分析，以检查应力和变形下的压缩。新颖之处在于梯度壁厚设计中的局部策略，以增强应力重分布。结果与均匀结构相比，梯度结构的比能吸收（SEA）沿加载方向和垂直于斜剪方向分别提高了18.3%和26.8%。从质量上讲，梯度设计减少了早期致密化，改善了应力再分布，为未来的设计提供了新的见解。综上所述，梯度设计和壁厚控制的策略应用显著提高了激光熔制316L不锈钢TPMS结构的SEA，具有广阔的应用前景。

{"title":"Tuning Energy Absorption of Metallic TPMS Cellular Structures via Wall Thickness Gradient Design","authors":"M. Zhong, W. Zhou, Z. Wu, J. Deng, Y. Du","doi":"10.1007/s11340-025-01190-1","DOIUrl":"10.1007/s11340-025-01190-1","url":null,"abstract":"<div><h3>Background</h3><p>In the study of laser melting fabricated 316L stainless steel triply periodic minimal surface (TPMS) structures, a knowledge gap persists. The understanding of optimizing deformation mechanisms and energy absorption, especially via gradient wall thickness design, remains inadequate.</p><h3>Objective</h3><p>The main aim of this research is to explore the deformation and energy absorption features of particular 316L stainless steel TPMS structures made by laser melting, emphasizing the use of gradient wall thickness design to improve overall energy absorption.</p><h3>Methods</h3><p>An integrated experimental and computational approach was developed. TPMS structures with diverse wall thicknesses were fabricated through laser melting. Then, detailed analyses were performed to examine stress and deformation under compression. The novelty was the local strategies in gradient wall thickness design for enhanced stress redistribution.</p><h3>Results</h3><p>Quantitatively, compared to uniform ones, the specific energy absorption (SEA) of gradient structures rose by 18.3% along the loading direction and 26.8% perpendicular to diagonal shearing. Qualitatively, the gradient design reduced early densification and improved stress redistribution, yielding new insights for future designs.</p><h3>Conclusions</h3><p>Overall, the strategic use of gradient design and wall thickness control significantly boosts the SEA of laser melting fabricated 316L stainless steel TPMS structures, showing great potential for future applications.</p></div>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"65 7","pages":"1043 - 1054"},"PeriodicalIF":2.4,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144843306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

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