Experimental Techniques最新文献

{"title":"Tribological Properties of EP Composites Reinforced with Short Glass Fiber, Graphite, PTFE and B4C Under Oil Lubrication","authors":"S. Xiong,&nbsp;Hong Kang","doi":"10.1007/s40799-024-00723-y","DOIUrl":"10.1007/s40799-024-00723-y","url":null,"abstract":"<div><p>Tribological performance of epoxy (EP) composites reinforced with short glass fibers (SGF), graphite, polytetrafluoroethylene (PTFE), and B₄C nanoparticles was investigated under oil lubrication. The effects of different types of SGF, graphite, PTFE, and B₄C nanoparticles on the friction and wear properties of EP were examined using a ball-on-block machine. The worn surfaces were characterized using optical microscopy, SEM-EDX, XPS, and TEM. The anti-wear mechanisms were proposed based on the experimental observations and analysis. The results demonstrate that the addition of SGF significantly reduces wear and friction in the EP matrix. In contrast, the incorporation of B₄C nanoparticles and other solid lubricants does not have a significant effect on friction and wear. The remarkable tribological properties observed in the SGF-reinforced EP composites can be attributed to the superior load-bearing capabilities and wear durability of SGF. These fibers effectively withstand the load and exhibit excellent durability during sliding, resulting in reduced wear and friction.</p></div>","PeriodicalId":553,"journal":{"name":"Experimental Techniques","volume":"49 1","pages":"169 - 179"},"PeriodicalIF":1.5,"publicationDate":"2024-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141259004","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}

{"title":"Study on the Friction and Wear Properties of Cast Iron Under Magnetic-Mechanical Coupling Conditions","authors":"Y. Chang,&nbsp;Y. Su,&nbsp;G. Chen,&nbsp;Y. Sun,&nbsp;C. Ren","doi":"10.1007/s40799-024-00724-x","DOIUrl":"10.1007/s40799-024-00724-x","url":null,"abstract":"<div><p>Cast iron is widely used as a grinding tool material in the field of ultra precision manufacturing. To explore the friction and wear properties of cast iron materials under magnetic-mechanical coupling conditions, theoretical research was conducted to reveal the wear mechanism of cast iron materials. A self-developed free abrasive line contact tribometer was used to study the evolution law of different process parameters on the friction and wear properties, surface roughness, and surface morphology of cast iron. The experimental results reveal that, under the magnetic field conditions, the mean value of friction coefficient is less than 0.218, the wear capacity of cast iron rings is less than 42 mg, and the surface roughness value Ra is less than 0.139 μm, additionally, the friction coefficient, wear capacity, and roughness values are all lower than those under no magnetic conditions. For cast iron materials, the surface roughness value Ra ranges from 0.094 to 0.253 μm after the experiment, it is negatively correlated with relative sliding ratio, load, abrasive particle size, and concentration, while is positively correlated with magnetic induction intensity; The friction coefficient is negatively correlated with relative sliding ratio and magnetic induction intensity in the range of 0.051 to 0.268, and positively correlated with abrasive particle size and concentration. With the load increasing, the friction coefficient first decreases and then increases; The wear capacity of cast iron ring is within the range of 8 to 140 mg. It is negatively correlated with magnetic induction intensity, and positively correlated with relative sliding ratio, load, abrasive particle size, and abrasive concentration. This study provides support for the theoretical research of cast iron as a grinding tool material and provides reference for the rational application of cast iron materials in the field of ultra precision manufacturing.</p></div>","PeriodicalId":553,"journal":{"name":"Experimental Techniques","volume":"49 1","pages":"59 - 84"},"PeriodicalIF":1.5,"publicationDate":"2024-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141259026","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}

{"title":"A Novel Method for Testing and Evaluating the Fatigue Life of Metal Vibration Absorber","authors":"Y. Peng,&nbsp;D. Jia,&nbsp;Z. Chen,&nbsp;Y. Gao,&nbsp;W. Zhong","doi":"10.1007/s40799-024-00721-0","DOIUrl":"10.1007/s40799-024-00721-0","url":null,"abstract":"<div><p>Metal vibration absorber has been widely used to reduce the structural vibration under various complex environmental conditions, the fatigue reliability of which has an important influence on the safety of the structure. In this paper, a novel fatigue failure criterion when the residual preload displacement of metal vibration absorber is equal to the fatigue displacement amplitude is proposed to determine the fatigue life of metal vibration absorber. And a set of fatigue failure life prediction method is developed to obtain the failure life of non-failed metal vibration absorber. The predicted load versus life (<i>P</i>-<i>N</i>) curve of the metal vibration absorber under different load levels shows a good power function relation. Based on the fatigue displacement amplitude-life curves and the residual preload displacement-life curves of the metal vibration absorbers, a fatigue failure assessment diagram is successfully established. Further, the residual fatigue failure life of in-service metal vibration absorber can also be predicted according to the failure assessment diagram. By means of the scanning electron microscopy and the three-dimensional tomography equipment, the microanalyses of metal wire components after fatigue tests are conducted, and the fatigue wear and fracture law of metal wire in the metal vibration absorber is mastered.</p></div>","PeriodicalId":553,"journal":{"name":"Experimental Techniques","volume":"49 1","pages":"45 - 57"},"PeriodicalIF":1.5,"publicationDate":"2024-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141105518","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}

{"title":"A Technique for In-Situ Displacement and Strain Measurement with Laboratory-Scale X-Ray Computed Tomography","authors":"O. L. Kafka,&nbsp;A. K. Landauer,&nbsp;J. T. Benzing,&nbsp;N. H. Moser,&nbsp;E. Mansfield,&nbsp;E. J. Garboczi","doi":"10.1007/s40799-024-00715-y","DOIUrl":"10.1007/s40799-024-00715-y","url":null,"abstract":"<p><b>Purpose</b>: Establish a technique for simultaneous interrupted volumetric imaging of internal structure and time-resolved full-field surface strain measurements during <i>in-situ</i> X-ray micro-computed tomography (XCT) experiments. This enables <i>in-situ</i> testing of stiff materials with large forces relative to the compliance of the <i>in-situ</i> load frame, which might exhibit localization (e.g., necking, compaction banding) and other inhomogeneous behaviors.<b>Methods</b>: The system utilizes a combination of <i>in-situ</i> XCT, 2D X-ray imaging, and particle tracking to conduct volumetric imaging of the internal structure of a specimen with interrupted loading and surface strain mapping during loading. Critically, prior to the laboratory-scale XCT experiments, specimens are speckled with a high-X-ray-contrast powder that is bonded the surface. During <i>in-situ</i> loading, the XCT system is programmed to capture sequential 2D X-ray images orthogonal to the speckled specimen surface. A single particle tracking (SPT) or digital image correlation (DIC) algorithm is used to measure full-field surface strain evolution throughout the time-sequence of images. At specified crosshead displacements, the motion and 2D image sequence is paused for volumetric XCT image collection. <b>Results</b>: We show example results on a micro-tensile demonstration specimen additive manufactured from Inconel 718 nickel-chrome alloy. Results include XCT volume reconstructions, crosshead-based engineering stress, and full-field strain maps. <b>Conclusion</b>: We demonstrate an <i>in-situ</i> technique to obtain surface strain evolution during laboratory-scale XCT testing and interrupted volumetric imaging. This allows closer investigation of, for example, the effect of micro-pores on the strain localization behavior of additive manufactured metal alloys. In addition to describing the method using a representative test piece, the dataset and code are published as open-source resources for the community.</p>","PeriodicalId":553,"journal":{"name":"Experimental Techniques","volume":"48 6","pages":"1101 - 1116"},"PeriodicalIF":1.5,"publicationDate":"2024-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s40799-024-00715-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141105032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Correction: Study on Roof Deformation and Failure Law of Close Distance Coal Seams Mining Based on Digital Image Correlation","authors":"S. L. Yang,&nbsp;Q. Li,&nbsp;H. Yue,&nbsp;D. Z. Kong,&nbsp;G. Y. Wu,&nbsp;S. Yang,&nbsp;F. Q. Liu","doi":"10.1007/s40799-024-00722-z","DOIUrl":"10.1007/s40799-024-00722-z","url":null,"abstract":"","PeriodicalId":553,"journal":{"name":"Experimental Techniques","volume":"48 4","pages":"757 - 757"},"PeriodicalIF":1.5,"publicationDate":"2024-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141116805","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}

{"title":"Enhancing Specimen Grip in Torsional Split Hopkinson Bar to Characterize Engineering Materials Under Pure Torsional Load","authors":"A. F. Fahem,&nbsp;A. T. Guthai,&nbsp;M. H. Mosa","doi":"10.1007/s40799-024-00719-8","DOIUrl":"10.1007/s40799-024-00719-8","url":null,"abstract":"<div><p>Torsional Split Hopkinson Bar (TSHB) is the primary apparatus used to generate non-dispersion shear waves and characterize material behavior under dynamic shear stress. However, challenges associated with specimen gripping, especially at high strain rate conditions have limited its application to low strain rates. In this work, a novel connection using a Male-Female built-in Hexagonal Joint (MFHJ) is proposed as an engineering solution to provide a strong connection between the torsional specimen and the input and output bars of the TSHB apparatus. The male hexagon is formed on the specimen tips and the female hexagon is formed on the input and output ends of the torsional Hopkinson bar. This technique is validated numerically and utilized experimentally to study the dynamic material responses of titanium-G5. This work describes the operating principle, numerical validation, and experimental setup of the TSHB apparatus, MFHJ manufacturing, and testing. The results indicate a stable and consistent loading rate in the specimen in addition to providing equilibrium conditions at a high strain rate.</p></div>","PeriodicalId":553,"journal":{"name":"Experimental Techniques","volume":"49 1","pages":"15 - 31"},"PeriodicalIF":1.5,"publicationDate":"2024-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141114477","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}

{"title":"Identification of Lightning Strike Damage Severity Using Pulse Thermography Through Integration of Thermal Data","authors":"T. M. Harrell,&nbsp;J. M. Dulieu-Barton,&nbsp;O. T. Thomsen","doi":"10.1007/s40799-024-00713-0","DOIUrl":"10.1007/s40799-024-00713-0","url":null,"abstract":"<div><p>Carbon fibre reinforced polymers (CFRP) structures, e.g., wind turbine blades, are suspectable to direct lightning strikes due to their semiconductive nature and ability to conduct current. It is critical to identify and evaluate lightning damage as it can cause premature failure of the primary load carrying components. Direct strike lightning damage has been traditionally identified and assessed by ultrasonic (UT) inspection, which is time consuming, usually requires contact, and does not directly provide a measure of damage severity. An appealing alternative to UT is pulsed thermography (PT), which takes minutes to conduct rather than hours and does not require a couplant. The aim of this work is to explore the application of pulse thermography to identify and evaluate the damage state of CFRP panels damaged by simulated lightning strike. A new analysis technique is presented that provides a damage severity metric which allows damage to be categorized, separated, and quantified.</p></div>","PeriodicalId":553,"journal":{"name":"Experimental Techniques","volume":"49 1","pages":"33 - 43"},"PeriodicalIF":1.5,"publicationDate":"2024-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s40799-024-00713-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141114482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Direct Drive Friction Welding Influence on Metallurgical, Mechanical, and Electrochemical Properties of AISI 316","authors":"A. J. Hassan,&nbsp;N. E. Titouche,&nbsp;S. A. Amzert,&nbsp;B. Cheniti,&nbsp;B. Belkessa,&nbsp;T. Boukharouba,&nbsp;D. Miroud","doi":"10.1007/s40799-024-00718-9","DOIUrl":"10.1007/s40799-024-00718-9","url":null,"abstract":"<div><p>This study examines the influence of direct drive friction welding (DDFW) on Cr-Ni-Mo steel (AISI 316) with a focus on metallurgical, mechanical, and electrochemical properties. Different friction times, ranging from 5.5 s to 12 s, were investigated while keeping other conditions constant. Temperature measurements, Macro-microstructure, microhardness, tensile tests, tensile fracture morphology, and electrochemical tests were performed. The results show that the maximum temperature (Tmax) exhibits a slight increase with an extended friction time. The temperature variation ranges from 826 °C to 879 °C for friction times of 5.5 s and 12 s, respectively, thus, the welded joint is divided into four distinct regions: highly plastically deformed zone (HPDZ), thermo-mechanically affected zone (TMAZ), heat-affected zone (HAZ), and the base metal, with grain sizes of approximately 10 μm, 100 μm, 110 μm, and 25 μm, respectively. The HPDZ is responsible for the microhardness elevation at the interface, while the TMAZ and HAZ are responsible for the microhardness attenuation in the neighboring region and weak in tension. The ultimate tensile strength (UTS) related to AISI 316 decreases from 104.50 to 94.57% for 5.5 s and 12 s, respectively, and the ductility related to AISI 316 decreases from 58.21 to 54.05% for 5.5 s and 12 s, respectively. Tensile fractures occurred at the TMAZ with a ductile fracture mode and cleavage features with irregular forms of microcavities throughout the fingerprints. The results of the electrochemical test clearly indicate that the weld zone (WZ) exhibits superior corrosion resistance compared to the base metal (BM), AISI 316. Further analysis of the results revealed that the TMAZs are more susceptible to pitting than the HAZ. Thus, only a few micro-pits are observed in the HPDZ compared to the pitting state in the TMAZs.</p></div>","PeriodicalId":553,"journal":{"name":"Experimental Techniques","volume":"49 1","pages":"151 - 167"},"PeriodicalIF":1.5,"publicationDate":"2024-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140979841","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}

{"title":"Study on Roof Deformation and Failure Law of Close Distance Coal Seams Mining Based on Digital Image Correlation","authors":"S. L. Yang,&nbsp;Q. Li,&nbsp;H. Yue,&nbsp;D. Z. Kong,&nbsp;G. Y. Wu,&nbsp;S. Yang,&nbsp;F. Q. Liu","doi":"10.1007/s40799-024-00717-w","DOIUrl":"10.1007/s40799-024-00717-w","url":null,"abstract":"<div><p>In order to research the laws of roof collapsing and overlaying stratum movement in close distance coal seams mining and prevent roof accidents during such mining. The close distance coal seams mining in a coal mine is used as the study subject in this study, and a similar simulation experiment is conducted. A similar simulation experiment of the close distance coal seams is seen using the digital image correlation. The evolution of roof displacement–strain in the mining process is researched, along with the roof caving features in various coal seam mining processes. The evolution law of roof stress-displacement is revealed in the mining process of close distance coal seams which provides the basis for the roof stability control in close distance coal seams. Lower coal seam mining in close distance coal seams has a larger degree of abutment pressure stress concentration and a higher level of advanced abutment pressure intensity. Greater harm is caused by lower coal seam roof strata mining than by single coal seam mining. The stope support strength design must take upper goaf influence into account. Therefore, to ensure the stope roof stability in close distance coal seams, it is necessary to implement roof pressure monitoring, stope roof’s grouting reinforcement, measures to improve the performance of hydraulic support, and roof effective control in close distance coal seams mining by using the principle of coordinated control.</p></div>","PeriodicalId":553,"journal":{"name":"Experimental Techniques","volume":"48 6","pages":"1005 - 1026"},"PeriodicalIF":1.5,"publicationDate":"2024-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140930420","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}

{"title":"Assessing Spatiotemporal Behavior of Human Gait: A Comparative Study Between Low-Cost Smartphone-Based Mocap and OptiTrack Systems","authors":"B. Castillo,&nbsp;C. Riascos,&nbsp;J. M. Franco,&nbsp;J. Marulanda,&nbsp;P. Thomson","doi":"10.1007/s40799-024-00716-x","DOIUrl":"10.1007/s40799-024-00716-x","url":null,"abstract":"<div><p>This study assessed the accuracy of a low-cost marker-based motion capture system with smartphone devices to estimate the spatiotemporal behavior of human gait in comparison with the performance of the commercial OptiTrack system. Initially, three test subjects were selected for the study, and after equipping them with passive retroreflective markers, they were recorded for gait velocities of 1.50, 1.90, and 2.30 <span>(mbullet {s}^{-1})</span> while collecting kinematic data and videos. The results showed that the smartphone motion capture system exhibited significant spatiotemporal tracking and accuracy in the x-y trajectories and estimation of joint relative angles of the hip, knee, and ankle joints (θ₁, θ₂, and θ₃, respectively) compared to the commercial OptiTrack system. In this comparison, an average goodness-of-FIT and normalized root mean square error of over 88.93% and 2.71% were obtained, respectively, for the joint relative angles of the hip and knee (θ₁ and θ2) in all tests performed. However, the accuracy of the joint relative angle of the ankle (θ3, average FIT: 71.04% and nRMSE: 4.26%) was lower because of the low capture rate of the retroreflective markers in the smartphone system and the higher relative velocity in the lower extremities of the test subjects, which generated noise in the calculation of x-y trajectories. This decrease in accuracy has been reported in other studies. However, both motion capture systems experienced marker data loss at the hip, highlighting the need for improvement in the spatial distribution of the optical devices. The OptiTrack system demonstrated better optical redundancy but still required improvements. In contrast, the smartphone system, with its inherent limitations in terms of optical redundancy and spatial distribution, can be enhanced by incorporating multiple cameras for a three-dimensional view. Despite these limitations, the low-cost smartphone system showed optimal performance with minimal errors compared with the commercial system, making it a cost-effective option with potential for further development. The rapid advancement of smartphone technology and its accessibility make it an attractive choice for motion capture applications.</p></div>","PeriodicalId":553,"journal":{"name":"Experimental Techniques","volume":"49 1","pages":"3 - 13"},"PeriodicalIF":1.5,"publicationDate":"2024-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s40799-024-00716-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140930564","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}