Pub Date : 2024-04-26DOI: 10.1007/s40799-024-00711-2
{"title":"On the Cover: Nine Point Bending Test Technique for Understanding of Sintered Silver Die Bonding Failure Mechanism","authors":"","doi":"10.1007/s40799-024-00711-2","DOIUrl":"https://doi.org/10.1007/s40799-024-00711-2","url":null,"abstract":"","PeriodicalId":553,"journal":{"name":"Experimental Techniques","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140799992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-23DOI: 10.1007/s40799-024-00709-w
L. Fang, Q. Gao, C. Zhou, B. Han, B. Ge
{"title":"Study on Velocity Distribution on Cross-Section Flow of T-Shunt","authors":"L. Fang, Q. Gao, C. Zhou, B. Han, B. Ge","doi":"10.1007/s40799-024-00709-w","DOIUrl":"https://doi.org/10.1007/s40799-024-00709-w","url":null,"abstract":"","PeriodicalId":553,"journal":{"name":"Experimental Techniques","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140671175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-12DOI: 10.1007/s40799-024-00707-y
S. S. Fayad, E.M.C. Jones, C. Winters
X-rays can provide images when an object is visibly obstructed, allowing for motion measurements via x-ray digital image correlation (DIC). However, x-ray images are path-integrated and contain data for all objects between the source and detector. If multiple objects are present in the x-ray path, conventional DIC algorithms may fail to correlate the x-ray images. A new DIC algorithm called path-integrated (PI)-DIC addresses this issue by reformulating the matching criterion for DIC to account for multiple, independently-moving objects. PI-DIC requires a set of reference x-ray images of each independent object. However, due to experimental constraints, such reference images might not be obtainable from the experiment. This work focuses on the reliability of synthetically-generated reference images, in such cases. A simplified exemplar is used for demonstration purposes, consisting of two aluminum plates with tantalum x-ray DIC patterns undergoing independent rigid translations. Synthetic reference images based on the “as-designed” DIC patterns were generated. However, PI-DIC with the synthetic images suffered some biases due to manufacturing defects of the patterns. A systematic study of seven identified defect types found that an incorrect feature diameter was the most influential defect. Synthetic images were re-generated with the corrected feature diameter, and PI-DIC errors were improved by a factor of 3-4. Final biases ranged from 0.00-0.04 px, and standard uncertainties ranged from 0.06-0.11 px. In conclusion, PI-DIC accurately measured the independent displacement of two plates from a single series of path-integrated x-ray images using synthetically-generated reference images, and the methods and conclusions derived here can be extended to more generalized cases involving stereo PI-DIC for arbitrary specimen geometry and motion. This work thus extends the application space of x-ray imaging for full-field DIC measurements of multiple surfaces or objects in extreme environments where optical DIC is not possible.
当物体受到明显遮挡时,X 射线可以提供图像,从而可以通过 X 射线数字图像相关(DIC)进行运动测量。然而,X 射线图像是路径整合的,包含光源和探测器之间所有物体的数据。如果 X 射线路径中存在多个物体,传统的 DIC 算法可能无法关联 X 射线图像。一种名为路径积分(PI)-DIC 的新型 DIC 算法通过重新制定 DIC 的匹配标准来考虑多个独立移动的物体,从而解决了这一问题。PI-DIC 需要每个独立物体的一组参考 X 射线图像。然而,由于实验的限制,这些参考图像可能无法从实验中获得。这项工作的重点是在这种情况下合成参考图像的可靠性。为了演示的目的,我们使用了一个简化的示例,它由两个带有钽 X 射线 DIC 图案的铝板组成,这两个铝板正在进行独立的刚性平移。根据 "设计 "的 DIC 图案生成合成参考图像。然而,由于图案的制造缺陷,使用合成图像的 PI-DIC 存在一些偏差。对七种已识别缺陷类型的系统研究发现,特征直径不正确是影响最大的缺陷。使用修正后的特征直径重新生成合成图像后,PI-DIC 误差提高了 3-4 倍。最终偏差范围为 0.00-0.04 px,标准不确定性范围为 0.06-0.11 px。总之,PI-DIC 利用合成生成的参考图像,从单个路径积分 X 射线图像系列中精确测量了两块板的独立位移,本文得出的方法和结论可扩展到涉及任意试样几何形状和运动的立体 PI-DIC 的更广泛情况。因此,这项工作扩展了 X 射线成像的应用空间,可在光学 DIC 无法实现的极端环境中对多个表面或物体进行全场 DIC 测量。
{"title":"Path-Integrated X-Ray Digital Image Correlation using Synthetic Reference Images","authors":"S. S. Fayad, E.M.C. Jones, C. Winters","doi":"10.1007/s40799-024-00707-y","DOIUrl":"https://doi.org/10.1007/s40799-024-00707-y","url":null,"abstract":"<p>X-rays can provide images when an object is visibly obstructed, allowing for motion measurements via x-ray digital image correlation (DIC). However, x-ray images are path-integrated and contain data for all objects between the source and detector. If multiple objects are present in the x-ray path, conventional DIC algorithms may fail to correlate the x-ray images. A new DIC algorithm called path-integrated (PI)-DIC addresses this issue by reformulating the matching criterion for DIC to account for multiple, independently-moving objects. PI-DIC requires a set of reference x-ray images of each independent object. However, due to experimental constraints, such reference images might not be obtainable from the experiment. This work focuses on the reliability of synthetically-generated reference images, in such cases. A simplified exemplar is used for demonstration purposes, consisting of two aluminum plates with tantalum x-ray DIC patterns undergoing independent rigid translations. Synthetic reference images based on the “as-designed” DIC patterns were generated. However, PI-DIC with the synthetic images suffered some biases due to manufacturing defects of the patterns. A systematic study of seven identified defect types found that an incorrect feature diameter was the most influential defect. Synthetic images were re-generated with the corrected feature diameter, and PI-DIC errors were improved by a factor of 3-4. Final biases ranged from 0.00-0.04 px, and standard uncertainties ranged from 0.06-0.11 px. In conclusion, PI-DIC accurately measured the independent displacement of two plates from a single series of path-integrated x-ray images using synthetically-generated reference images, and the methods and conclusions derived here can be extended to more generalized cases involving stereo PI-DIC for arbitrary specimen geometry and motion. This work thus extends the application space of x-ray imaging for full-field DIC measurements of multiple surfaces or objects in extreme environments where optical DIC is not possible.</p>","PeriodicalId":553,"journal":{"name":"Experimental Techniques","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140595294","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-11DOI: 10.1007/s40799-024-00708-x
T. Fourest
Digital Images Correlation (DIC) measures are widely used in order to calibrate models. It is very common for researchers to use filters on these measurements to improve the measurement resolution (decrease the noise level) before using them with various methodologies. However, the effects of these filters on the tradeoff between spatial resolution and measurement resolution are not fully understood. The objective of the study is to compare seven common denoising/filtering methods for 2D DIC with affine subset shape function, including image filters (Gaussian, Median), frequency filters (Lowpass Butterworth, Holoborodko), local polynomial fitting (Savitzky-Golay filter, cubic splines), and Finite Elements mapping. The proposed methodology to compare the enhancement of these methods is based on the star pattern test cases used in the DIC Challenge 2.0. Hence, this study aims to obtain a general comparison of the filtering methods as opposed to case-dependent approaches. To that end, firstly, the FOLKI-D DIC code is metrologically qualified using the DIC Challenge 2.0 methodology and test cases. Then, the filtering methods are applied to the displacements and strain maps computed with the FOLKI-D code for various DIC subset sizes and filter parameters. It is found that displacement and strain map enhancements vary significantly depending on the filter. Some methods show no improvement (or worsened tradeoff in the strain case), while others achieve similar resolution tradeoffs as DIC codes using quadratic subset shape functions. Finally, it is concluded that the filter choice significantly impacts results, with higher-order lowpass Butterworth, Savitzky-Golay, and Finite Elements mapping methods showing preference over others studied.
{"title":"Optimizing Metrological Efficiency: Comparative Analysis of Filtering Methods for 2D DIC","authors":"T. Fourest","doi":"10.1007/s40799-024-00708-x","DOIUrl":"https://doi.org/10.1007/s40799-024-00708-x","url":null,"abstract":"<p>Digital Images Correlation (DIC) measures are widely used in order to calibrate models. It is very common for researchers to use filters on these measurements to improve the measurement resolution (decrease the noise level) before using them with various methodologies. However, the effects of these filters on the tradeoff between spatial resolution and measurement resolution are not fully understood. The objective of the study is to compare seven common denoising/filtering methods for 2D DIC with affine subset shape function, including image filters (Gaussian, Median), frequency filters (Lowpass Butterworth, Holoborodko), local polynomial fitting (Savitzky-Golay filter, cubic splines), and Finite Elements mapping. The proposed methodology to compare the enhancement of these methods is based on the star pattern test cases used in the DIC Challenge 2.0. Hence, this study aims to obtain a general comparison of the filtering methods as opposed to case-dependent approaches. To that end, firstly, the FOLKI-D DIC code is metrologically qualified using the DIC Challenge 2.0 methodology and test cases. Then, the filtering methods are applied to the displacements and strain maps computed with the FOLKI-D code for various DIC subset sizes and filter parameters. It is found that displacement and strain map enhancements vary significantly depending on the filter. Some methods show no improvement (or worsened tradeoff in the strain case), while others achieve similar resolution tradeoffs as DIC codes using quadratic subset shape functions. Finally, it is concluded that the filter choice significantly impacts results, with higher-order lowpass Butterworth, Savitzky-Golay, and Finite Elements mapping methods showing preference over others studied.</p>","PeriodicalId":553,"journal":{"name":"Experimental Techniques","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140595300","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-04DOI: 10.1007/s40799-024-00706-z
Z. Ren, X. Qin, Q. Zhang, Y. Sun
The Chaudonneret model cannot fully and effectively characterize the linear correlation between the strain energy density release rate and the number of cycles in the damage evolution stage of low carbon alloy steels under multiaxial non-proportional loading. In order to solve this problem, the fatigue failure process of Q355B is captured by digital image correlation technology, and the factors affecting fatigue failure under multiaxial loading are analyzed in combination with fracture morphology characteristics. Based on the concept of critical plane, a new stress combination form is introduced to reflect the failure factors, and the corresponding damage evolution model is proposed. The model considers the interaction between different stresses and can describe the damage evolution law under non-proportional loading. Compared with different types of life prediction models, the distribution range of life prediction results of the improved model under multiaxial non-proportional loading has a good correlation with the experimental values.
{"title":"Damage Evolution Model Considering Fatigue Failure Factor Under Multiaxial Non-Proportional Loading","authors":"Z. Ren, X. Qin, Q. Zhang, Y. Sun","doi":"10.1007/s40799-024-00706-z","DOIUrl":"https://doi.org/10.1007/s40799-024-00706-z","url":null,"abstract":"<p>The Chaudonneret model cannot fully and effectively characterize the linear correlation between the strain energy density release rate and the number of cycles in the damage evolution stage of low carbon alloy steels under multiaxial non-proportional loading. In order to solve this problem, the fatigue failure process of Q355B is captured by digital image correlation technology, and the factors affecting fatigue failure under multiaxial loading are analyzed in combination with fracture morphology characteristics. Based on the concept of critical plane, a new stress combination form is introduced to reflect the failure factors, and the corresponding damage evolution model is proposed. The model considers the interaction between different stresses and can describe the damage evolution law under non-proportional loading. Compared with different types of life prediction models, the distribution range of life prediction results of the improved model under multiaxial non-proportional loading has a good correlation with the experimental values.</p>","PeriodicalId":553,"journal":{"name":"Experimental Techniques","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140595303","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-04DOI: 10.1007/s40799-024-00705-0
{"title":"On the Cover: High‑Order Time‑Domain DIC Algorithm Based on a Nonlinear Optical Flow Equation","authors":"","doi":"10.1007/s40799-024-00705-0","DOIUrl":"https://doi.org/10.1007/s40799-024-00705-0","url":null,"abstract":"","PeriodicalId":553,"journal":{"name":"Experimental Techniques","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140033225","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-21DOI: 10.1007/s40799-024-00703-2
A.N. Kivanani, S. Khalilpourazary, F. Mobadersani
Cooling by micro-channel heat sink transfers excess heat flux in electrical devices and increases their functional capacity, reliability, and life span. In this paper, AlSi10Mg powders were employed to create four micro-channel heat sinks with cross-sections including square, rectangle, circle, and ellipse with an additive manufacturing method. To investigate the impact of micro-channel heat sink cross-sectional geometry on thermal resistance, Taguchi’s L25 orthogonal array was utilized. Reynolds number and electric power were selected to be the input parameters. The experimental tests were conducted using an experimental setup and distilled water as the working fluid in the laminar flow regime. The results obtained from the experimental tests indicated that in the range of electric power from 4 to 12 W and Reynolds numbers of 50, 100, 150, 200, and 250, the micro-channel heat sink with a square cross-section exhibits the highest heat transfer performance. Finally, an analysis of variance was conducted to study the impact of the Reynolds number and electric power factors on thermal resistance. The findings revealed the significant effect of electric power on thermal resistance in micro-channel heat sinks compared to the Reynolds number in the laminar regime. Additionally, a comparison was made with other available results.
{"title":"An Experimental Study on the Dependency of Thermal Resistance of Additively Manufactured Micro-Channel Heat Sinks on Channel Cross-Sections","authors":"A.N. Kivanani, S. Khalilpourazary, F. Mobadersani","doi":"10.1007/s40799-024-00703-2","DOIUrl":"https://doi.org/10.1007/s40799-024-00703-2","url":null,"abstract":"<p>Cooling by micro-channel heat sink transfers excess heat flux in electrical devices and increases their functional capacity, reliability, and life span. In this paper, AlSi10Mg powders were employed to create four micro-channel heat sinks with cross-sections including square, rectangle, circle, and ellipse with an additive manufacturing method. To investigate the impact of micro-channel heat sink cross-sectional geometry on thermal resistance, Taguchi’s L25 orthogonal array was utilized. Reynolds number and electric power were selected to be the input parameters. The experimental tests were conducted using an experimental setup and distilled water as the working fluid in the laminar flow regime. The results obtained from the experimental tests indicated that in the range of electric power from 4 to 12 W and Reynolds numbers of 50, 100, 150, 200, and 250, the micro-channel heat sink with a square cross-section exhibits the highest heat transfer performance. Finally, an analysis of variance was conducted to study the impact of the Reynolds number and electric power factors on thermal resistance. The findings revealed the significant effect of electric power on thermal resistance in micro-channel heat sinks compared to the Reynolds number in the laminar regime. Additionally, a comparison was made with other available results.</p>","PeriodicalId":553,"journal":{"name":"Experimental Techniques","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139917726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-21DOI: 10.1007/s40799-024-00702-3
A. A. Jaber, L. A. Al-Haddad
Due to the extensive use of Unmanned Aerial Vehicles (UAVs) and the co-evolution of current technology, a key introduction to fault detection has arisen in recent studies in order to prevent unfortunate consequences. In this study, vibration-based signals from a commercially available innovative quadcopter flying in hover mode are collected using a vibration accelerometer, a data acquisition device, and a laptop. An ADXL335 accelerometer is fixed on the center of the drone where the centerlines of the four blades intersect. The superposition of numerous vibration arrangements over identical spectra hinders the ability to analyze the spectral data in the manner required to locate any framework's discrete vibration. This work presents a technique for separating a synthesized vibration signal towards discrete vibrations and other extraneous vibrations of a structure utilizing the Discrete Wavelet Transform (DWT) integrated with the Fast Fourier Transform (FFT). The research article findings in this study demonstrate the reliability and applicability of specific categories of discrete vibrations that are sorted out during the structural change evaluation to develop the best feasible strategy for removing the undesired and unanticipated vibration components and noise. The methodology demonstrated in this paper has the potential for practical application to multirotor UAVs in general.
{"title":"Integration of Discrete Wavelet and Fast Fourier Transforms for Quadcopter Fault Diagnosis","authors":"A. A. Jaber, L. A. Al-Haddad","doi":"10.1007/s40799-024-00702-3","DOIUrl":"https://doi.org/10.1007/s40799-024-00702-3","url":null,"abstract":"<p>Due to the extensive use of Unmanned Aerial Vehicles (UAVs) and the co-evolution of current technology, a key introduction to fault detection has arisen in recent studies in order to prevent unfortunate consequences. In this study, vibration-based signals from a commercially available innovative quadcopter flying in hover mode are collected using a vibration accelerometer, a data acquisition device, and a laptop. An ADXL335 accelerometer is fixed on the center of the drone where the centerlines of the four blades intersect. The superposition of numerous vibration arrangements over identical spectra hinders the ability to analyze the spectral data in the manner required to locate any framework's discrete vibration. This work presents a technique for separating a synthesized vibration signal towards discrete vibrations and other extraneous vibrations of a structure utilizing the Discrete Wavelet Transform (DWT) integrated with the Fast Fourier Transform (FFT). The research article findings in this study demonstrate the reliability and applicability of specific categories of discrete vibrations that are sorted out during the structural change evaluation to develop the best feasible strategy for removing the undesired and unanticipated vibration components and noise. The methodology demonstrated in this paper has the potential for practical application to multirotor UAVs in general.</p>","PeriodicalId":553,"journal":{"name":"Experimental Techniques","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139945715","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-17DOI: 10.1007/s40799-024-00704-1
J. Tabin, A. Brodecki
This paper presents a novel measurement method that aims to qualitatively and quantitatively assess uniform deformation during displacement- and force-controlled tensile tests of ductile metals. The method utilizes digital image correlation technology to record the strain distribution during tensile testing, followed by the calculation of the floating root mean square (RMS) value of the strain amplitude along the specimen axis. By implementing this approach, the RMS-based profiles of strain amplitude are identified in different metals and alloys, including austenitic stainless steels, structural steel, copper, and aluminium alloys. Moreover, the proposed method holds potential for predicting important deformation characteristics such as distribution of intensive plastic zones, necking effect, and delocalization effect. Thus, it establishes a link between macroscale and microscale during the analysis of plastic deformation behaviour. The effectiveness of the new method is compared with existing strain and strain-rate methods. The novel approach demonstrates promising advantages in the context of the identification of metal-forming parameters.
{"title":"Parametrisation of Uniform Deformation in Ductile Metals Using Digital Image Correlation Technology","authors":"J. Tabin, A. Brodecki","doi":"10.1007/s40799-024-00704-1","DOIUrl":"https://doi.org/10.1007/s40799-024-00704-1","url":null,"abstract":"<p>This paper presents a novel measurement method that aims to qualitatively and quantitatively assess uniform deformation during displacement- and force-controlled tensile tests of ductile metals. The method utilizes digital image correlation technology to record the strain distribution during tensile testing, followed by the calculation of the floating root mean square (RMS) value of the strain amplitude along the specimen axis. By implementing this approach, the RMS-based profiles of strain amplitude are identified in different metals and alloys, including austenitic stainless steels, structural steel, copper, and aluminium alloys. Moreover, the proposed method holds potential for predicting important deformation characteristics such as distribution of intensive plastic zones, necking effect, and delocalization effect. Thus, it establishes a link between macroscale and microscale during the analysis of plastic deformation behaviour. The effectiveness of the new method is compared with existing strain and strain-rate methods. The novel approach demonstrates promising advantages in the context of the identification of metal-forming parameters.</p>","PeriodicalId":553,"journal":{"name":"Experimental Techniques","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139902645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-08DOI: 10.1007/s40799-024-00701-4
C. Pongratz, J. Tix, J. Wolfrum, S. Gerke, I. Ehrlich, M. Brünig
Instrumented impact testing and compression-after-impact testing are important to adequately qualify material behavior and safely design composite structures. However, the stresses to which fiber-reinforced plastic components are typically subjected in practice are not considered in the impact test methods recommended in guidelines or standards. In this paper, a test setup for investigating the impact behavior of composite specimens under plane uniaxial and biaxial preloading is presented. For this purpose, a special test setup consisting of a biaxial testing machine and a specially designed drop-weight tower was developed. The design decisions were derived from existing guidelines and standards with the aim of inducing barely visible impact damage in laminated carbon fiber-reinforced plastic specimens. Several measurement systems have been integrated into the setup to allow comprehensive observation of the impact event and specimen behavior. A feasibility test was performed with biaxially prestressed carbon fiber-reinforced plastic specimens in comparison with unstressed reference tests. The compressive-tensile prestressing resulted in lower maximum contact forces, higher maximum deflections, higher residual deflections and a different damage pattern, which was investigated by light microscopic analysis. Finally, the functionality of the experimental setup is discussed, and the results seem to indicate that the test setup and parameters were properly chosen to investigate the effect of prestresses on the impacts behavior of composite structures, in particular for barely visible subsequent damages.
{"title":"Test Setup for Investigating the Impact Behavior of Biaxially Prestressed Composite Laminates","authors":"C. Pongratz, J. Tix, J. Wolfrum, S. Gerke, I. Ehrlich, M. Brünig","doi":"10.1007/s40799-024-00701-4","DOIUrl":"https://doi.org/10.1007/s40799-024-00701-4","url":null,"abstract":"<p>Instrumented impact testing and compression-after-impact testing are important to adequately qualify material behavior and safely design composite structures. However, the stresses to which fiber-reinforced plastic components are typically subjected in practice are not considered in the impact test methods recommended in guidelines or standards. In this paper, a test setup for investigating the impact behavior of composite specimens under plane uniaxial and biaxial preloading is presented. For this purpose, a special test setup consisting of a biaxial testing machine and a specially designed drop-weight tower was developed. The design decisions were derived from existing guidelines and standards with the aim of inducing barely visible impact damage in laminated carbon fiber-reinforced plastic specimens. Several measurement systems have been integrated into the setup to allow comprehensive observation of the impact event and specimen behavior. A feasibility test was performed with biaxially prestressed carbon fiber-reinforced plastic specimens in comparison with unstressed reference tests. The compressive-tensile prestressing resulted in lower maximum contact forces, higher maximum deflections, higher residual deflections and a different damage pattern, which was investigated by light microscopic analysis. Finally, the functionality of the experimental setup is discussed, and the results seem to indicate that the test setup and parameters were properly chosen to investigate the effect of prestresses on the impacts behavior of composite structures, in particular for barely visible subsequent damages.</p>","PeriodicalId":553,"journal":{"name":"Experimental Techniques","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139767283","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}