Experimental Techniques最新文献

{"title":"Influence of Using SiC and Al2O3 Ceramic Front Layer on Ballistic Performance of a Bainitic Steel: A Comparative Study","authors":"S. Önder,&nbsp;E. Özer,&nbsp;M. Übeylі","doi":"10.1007/s40799-024-00745-6","DOIUrl":"10.1007/s40799-024-00745-6","url":null,"abstract":"<div><p>Development of lightweight armors is vital in order to provide ballistic protection in a more effective way. The weight of steel armor can be decreased significantly by setting a front ceramic layer on it. In this paper, the influence of utilizing SiC and Al₂O₃ ceramic front layer on the ballistic behavior of 4140 bainitic steel was investigated experimentally. All steel plates were initially subjected to the austempering treatment by applying the austenitization at 860 °C for 1 h and then holding in a salt bath at 343 °C for 50 min to get fully bainitic microstructure. And then, the laminated composites, consisting of SiC or Al₂O₃ front layer (50 × 50 mm in size) and bainitic steel backing layer, were prepared by joining these layers with an acrylic adhesive. After the mechanical and microstructural characterization of the bainitic steel, the ballistic shots were made using 7.62 × 51 mm AP projectile with an average speed of 788.4 m/s on both monolithic steel and layered armor samples for comparison. The samples, which stopped the bullet at normal impact condition without complete perforation or disintegration of the bainitic steel layer, were termed as successful. The bainitic steel achieved the ballistic protection at a thickness ≥ 14 mm but the use of SiC layer provided the weight saving of at least 42.9% and the Al₂O₃ front layer enabled the weight reduction of 28.6% in the armor with respect to the monolithic 4140 bainitic steel.</p></div>","PeriodicalId":553,"journal":{"name":"Experimental Techniques","volume":"49 2","pages":"267 - 277"},"PeriodicalIF":1.5,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142222271","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":"An Experiment for the Validation of Force Reconstruction Techniques on Flexible Structures","authors":"Z. T. Jones,&nbsp;N. A. Vlajic","doi":"10.1007/s40799-024-00738-5","DOIUrl":"10.1007/s40799-024-00738-5","url":null,"abstract":"<div><p>Dynamic force measurements are often corrupted by the structural dynamics of the surrounding support structure. Force reconstruction techniques aim to correct for these structural effects by using additional information such as a modal characterization of the structure, a finite element model of the assembly, or additional instrumentation. In practice, accurately measuring input forces to validate the techniques is often difficult or impossible. This work proposes a novel experiment that allows for measurement of the true input spatial force distribution acting on a structure for the purposes of experimentally validating force reconstruction techniques. In the proposed experiment, independently-controlled electromagnets are supported by force gages and used to excite a flexible structure. The reaction force from the electromagnet gives a measure of the applied forces over a given bandwidth, which can be used to validate force reconstruction techniques. This paper focuses on the design of such an experimental arrangement, and presents a numerical model which can also be used to validate force reconstruction techniques. Key components of this experiment are characterized to validate the measurements and methodology. The independently-controlled electromagnets can mimic different types of physical excitation forces, which allow for validation of various force reconstruction techniques aimed at niche applications. For example, the main application of the proposed experiment is to reconstruct unsteady fluid-borne forces generated on a flexible test structure. As such, a sample measurement mimicking forces generated by turbulent flow across a beam using electromagnets is provided.</p></div>","PeriodicalId":553,"journal":{"name":"Experimental Techniques","volume":"49 2","pages":"351 - 368"},"PeriodicalIF":1.5,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142222274","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":"Designing a Flexural Fatigue Machine for Characterization of 3d Printed Materials: An Approach Using the Third Law of Newton","authors":"I. Pereyra,&nbsp;M. A. González-López,&nbsp;L. E. Lugo-Uribe,&nbsp;M. Dehonor-Gomez,&nbsp;G. M. de Oca-Ramírez,&nbsp;N. Jardón-Maximino,&nbsp;A. Gallegos-Melgar,&nbsp;M. Hernández-Hernández,&nbsp;J. Mayen","doi":"10.1007/s40799-024-00742-9","DOIUrl":"10.1007/s40799-024-00742-9","url":null,"abstract":"<div><p>In this study, a novel flexural fatigue testing apparatus was designed to evaluate the fatigue behavior of 3D-printed materials. The machine was validated using polylactic acid (PLA) 3D-printed samples and fiber-reinforced thermoformed polypropylene (PP). The investigation focused on the effects of varying infill percentages of PLA and fiber reinforcement in PP under constant deflection, in accordance with Newton’s third law. The results provided significant insights into the fatigue life of these materials, including stiffness degradation and damage accumulation, thereby confirming the machine’s efficacy. This research contributes to a deeper understanding of 3D-printed material behavior under cyclic loading and enhances the machine’s capability to assess both conventional and specialized plastics. Furthermore, we compared the indirect measurement of elastic modulus obtained from fatigue testing with direct measurements for various percentages of reinforced PP, demonstrating the feasibility of deriving elastic modulus from fatigue testing.</p></div>","PeriodicalId":553,"journal":{"name":"Experimental Techniques","volume":"49 2","pages":"235 - 252"},"PeriodicalIF":1.5,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142222272","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":"Effects of Horn Type on the Microhardness and Microstructural Homogeneity in Ultrasonic-Assisted Simple Shear Extrusion","authors":"M. Balali,&nbsp;S. M. H. Seyedkashi,&nbsp;A. Hasanabadi,&nbsp;H. Gorji,&nbsp;H. Baseri,&nbsp;M. Khosravi","doi":"10.1007/s40799-024-00744-7","DOIUrl":"10.1007/s40799-024-00744-7","url":null,"abstract":"<div><p>The objective of this study was to minimize the friction force within the deformation zone in the simple shear extrusion (SSE) process by utilizing the ultrasonic vibrations directly on pure copper samples. Modal analysis was conducted on two types of horns (cylindrical-exponential-cylindrical and cylindrical-conical-cylindrical) to determine an efficient concentrator. Two punch feed rates of 5 and 10 mm/min, a frequency of 20 kHz, and an amplitude of 15 micrometers were employed in this ultrasonic-assisted simple shear extrusion (USSE) method. The homogeneity of microhardness and microstructure was investigated in both SSE and USSE methods. The findings implied that during the initial pass of the SSE method, the mechanical and microstructural properties were improved by increasing the feed rate; however, no improvement in the microstructural homogeneity was observed in the same pass. In contrast, the USSE process demonstrated enhancements in the mechanical and microstructural properties at a lower feed rate. Furthermore, a significant improvement in the homogeneity of the microhardness and microstructure was reported in USSE due to the uniform distribution of strain under ultrasonic vibrations in the samples. This enhancement was achieved in the first pass of USSE, whereas it occurred in subsequent passes in the SSE method. The cylindrical-exponential-cylindrical horn exhibited a more significant role in improving the homogeneity and mechanical properties compared to the cylindrical-conical-cylindrical horn due to its good concentration and transmission of vibrations.</p></div>","PeriodicalId":553,"journal":{"name":"Experimental Techniques","volume":"49 2","pages":"253 - 266"},"PeriodicalIF":1.5,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142222273","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":"On the Cover: Test Setup for Investigating the Impact Behavior of Biaxially Prestressed Composite Laminates","authors":"","doi":"10.1007/s40799-024-00741-w","DOIUrl":"10.1007/s40799-024-00741-w","url":null,"abstract":"","PeriodicalId":553,"journal":{"name":"Experimental Techniques","volume":"48 5","pages":"759 - 759"},"PeriodicalIF":1.5,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142222294","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 Cavitation Corrosion Resistance of Supersonic Flame Spraying WC-10Co4Cr Coating on Aero-Engine Fuel Pump","authors":"Q. Ding,&nbsp;Y. Li,&nbsp;H. Yu,&nbsp;Y. Cui,&nbsp;F. Xiao","doi":"10.1007/s40799-024-00737-6","DOIUrl":"10.1007/s40799-024-00737-6","url":null,"abstract":"<div><p>ZL101 cast aluminum alloy was the main material of the aircraft engine fuel pump, and it was damaged by cavitation. In order to mitigate the cavitation-induced damage of the aero-engine fuel pump, we investigated the protection ability of WC-10Co4Cr (tungsten carbide alloy powder) coating prepared on the surface through supersonic flame spraying technology. The quality of the coating was evaluated from five aspects, and cavitation experiments were conducted with an ultrasonic vibration device. The results of the study showed that the WC-10Co4Cr coating prepared with a spraying distance of 360 mm, powder feed rate of 80 g/min, gun moving speed of 800 mm/s, and chamber pressure of 6.8 MPa had the highest microhardness value of 1059.5 HV0.3 and the lowest porosity of 1.09%, and it indicated the optimal coating quality. Although the coating surface still exhibited cracks and cavitation voids under cavitation, the extent of cracking and voids was significantly improved compared to the untreated control group.The cumulative volume loss of the coating after 480 min of cavitation was 4.84 mm³, accounting for 25.1% of the volume loss in the untreated control group. Under the same cavitation duration, the volume loss rate of the coating was consistently lower than that of the cast aluminum alloy. This study demonstrated that supersonic flame spraying WC-10Co4Cr coating on the surface of the fuel pump could reduce the rate of cavitation-induced damage, proper coating selection could enhance the material’s resistance to cavitation and provide more options for cavitation protection.</p></div>","PeriodicalId":553,"journal":{"name":"Experimental Techniques","volume":"49 2","pages":"219 - 234"},"PeriodicalIF":1.5,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142222275","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":"Novel Hydro-Pneumatic Interconnected Suspension Integrating Pipe-Connected Magnetorheological Valve Designed Based on Magnetic Gradient Pinch Mode—Experimental Study and Modelling","authors":"D. Lin,&nbsp;F. Yang,&nbsp;R. Li,&nbsp;W. Zhang,&nbsp;D. Gong","doi":"10.1007/s40799-024-00739-4","DOIUrl":"10.1007/s40799-024-00739-4","url":null,"abstract":"<p>Recently, passive Hydro-pneumatic Interconnected Suspension (HIS) has been utilized in commercial vehicles due to its outstanding handling performance. However, it cannot satisfy the working requirement over the whole working frequency range due to the fixed damping property. In order to provide the continuously tunable damping and satisfy the large flow rate requirement of HIS device, a novel HIS integrating pipe-connected Magnetorheological valve (MGPMR valve) designed based on Magnetic Gradient Pinch Mode, is proposed in this study. The designed MGPMR valve is suitable for the large flow rate working condition of HIS system together with the stackable property through series connection of number of MGPMR valves to achieve the required damping properties. Based on the designed experimental, it has been shown that the designed pipe-connected single MGPMR valve can reach 735% tunable range of the damping property under 1.234×10^–4 m³/s sinusoidal flow rate signal. The dynamic property of the novel HIS is described by the established model considering the ideal gas law with Energy Equation, fluid inertial and laminar flow between the connection pipes, and piston frictions, together with pressure drop property of MGPMR valve described by the hyperbolic tangent hysteresis model, and the validity of the dynamic model is verified by the laboratory test. Finally, based on a roll-plane vehicle simulation model, the effect of the tunable damping property for the novel HIS is evaluated based on the frequency domain analysis and responses under the road transient and lateral acceleration excitations. The results show that compared with the traditional HIS (without MGPMR valve), the vertical/roll vibration isolating properties and anti-roll performance of the vehicle model can be improved through modifying the applied current of pipe-connected MGPMR valves, which provides the application potential to achieve continuously tunable damping in the semi-active HIS design.</p>","PeriodicalId":553,"journal":{"name":"Experimental Techniques","volume":"49 2","pages":"203 - 217"},"PeriodicalIF":1.5,"publicationDate":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142222276","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":"Automated Method for Pre-Straining of Steels for Bake Hardenability Testing","authors":"A. Agha","doi":"10.1007/s40799-024-00735-8","DOIUrl":"10.1007/s40799-024-00735-8","url":null,"abstract":"<div><p>The bake hardening effect in steel, characterized by a boost in yield strength resulting from initial deformation and subsequent heat treatment, holds significant promise for the automotive sector. Bake hardening is characterized by the Bake Hardening Index (BHI), as outlined in the test standards EN 10325:2006 and JIS G 3135:2018. The suggested test procedure involves pre-straining the dogbone samples and subjecting them to thermal cycling. However, the current standards lack specificity regarding the pre-straining procedure and the estimation of elastic recovery in metals, leading to inconsistencies in results across different materials and laboratories. This study addresses this gap by proposing a standardized and fully automated method utilizing in-situ strain measurements to precisely pre-strain uniaxial tension samples to any desired level of plastic strain. This method offers precise control over strains and accurate estimation of strain overcompensation, which accounts for elastic recovery during unloading. In this paper, the proposed method is validated using optical strains using digital image correlation, however the proposed method is independent of the choice of strain measurement method and works with clip-on extensometers, optical extensometers and even the crosshead transducers in the load frame. The foundation and effectiveness of the proposed method are demonstrated through statistical data obtained from testing 11 different steel grades, including bake hardenable steels and Advanced High Strength Steels commonly used in the automotive industry. The proposed method is independent of the choice of steel grade and consistently delivers satisfactory results for all tested steel grades, producing test samples with plastic strains that adhere to the specifications of the testing standards.</p></div>","PeriodicalId":553,"journal":{"name":"Experimental Techniques","volume":"49 1","pages":"181 - 186"},"PeriodicalIF":1.5,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141927923","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":"Extraction of the Descriptive Function of a Folding Wing With Free-Play Using the Modal Test Results to Be Used in the Nonlinear Motion Equation of the Structure","authors":"M. Ghadimi,&nbsp;R. Azarafza,&nbsp;A. Davar,&nbsp;J.E. Jam","doi":"10.1007/s40799-024-00734-9","DOIUrl":"10.1007/s40799-024-00734-9","url":null,"abstract":"<div><p>Structures can exhibit non-linear behavior due to the presence of free-play. To analyze this behavior, different numerical and analytical methods like the substructure synthesis method or the harmonic balance method are used. To determine the effect of non-linarites caused by free-play, descriptive functions must be identified. The restoring force approach is frequently used in systems where mass and stiffness matrices are known, such as finite element models. Another approach involves frequency response functions obtained through vibration tests.</p><p>This article discusses the second approach, which involves extracting the free-play function using frequency response functions obtained from tests. The tests include a modal test with random excitation to determine the frequency response functions for the linear mode of the modes with low excitation amplitude. Additionally, sinusoidal excitation is used with increasing amplitude for the frequency response functions in the nonlinear state of the modes. The laboratory method used to determine the nonlinear modes involves increasing the amplitude of sinusoidal stimulation in the frequency range of each resonance. This article presents a practical method for analyzing the dynamic behavior of structures related to the folding wing of a flying system. Using simple techniques and vibration test results, it deals with extracting the free-play function of the structure.</p></div>","PeriodicalId":553,"journal":{"name":"Experimental Techniques","volume":"49 1","pages":"137 - 149"},"PeriodicalIF":1.5,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141938914","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":"Vertical Projectile Launcher for Study of Rapid Penetration into Soil Targets","authors":"L. Giacomo,&nbsp;D. Grace,&nbsp;M. Omidvar,&nbsp;S. Bless,&nbsp;M. Iskander","doi":"10.1007/s40799-024-00732-x","DOIUrl":"10.1007/s40799-024-00732-x","url":null,"abstract":"<div><p>The majority of ballistic experiments in granular media in the literature involve horizontally launching projectiles. Notwithstanding the significant scientific findings resulting from these studies, the depth-dependence of geostatic stresses is not captured in a horizontal configuration. The design and performance of a vertical ballistic range is described herein. The range is capable of launching projectiles at impact speeds of up to 900 m/s into soil targets. A pluviator is employed to prepare sand targets with precise and highly repeatable bulk densities. Use of a photon Doppler velocimeter (PDV) and other instrumentation to track projectile velocity both in-flight and during penetration into the soil target are elucidated. A relationship is found between the muzzle velocity and chamber pressure. Launcher performance is quantified by comparing measured muzzle velocities with theoretical velocities calculated from isentropic expansion of gas behind the projectile in the launcher barrel. It is found that the launcher efficiency is in the range of 70 to 90%, with efficiency increasing for heavier projectiles. The PDV instrumentation developed for the range successfully resolves projectile velocities in flight and during penetration into the soil target.</p></div>","PeriodicalId":553,"journal":{"name":"Experimental Techniques","volume":"48 6","pages":"1077 - 1092"},"PeriodicalIF":1.5,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141773383","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}