International Journal of Impact Engineering最新文献

{"title":"Fracture mechanics of ceramic layers in composite armor: Effects of impact velocity","authors":"Yilei Yu,&nbsp;Yiding Wu,&nbsp;Minghui Ma,&nbsp;Wencheng Lu,&nbsp;Guangfa Gao","doi":"10.1016/j.ijimpeng.2024.105211","DOIUrl":"10.1016/j.ijimpeng.2024.105211","url":null,"abstract":"<div><div>This paper presents an analysis of the dynamic impact behavior and fracture mechanics of ceramic/metal composite armor under ballistic penetration. Utilizing 12.7 mm armor-piercing incendiary rounds for experimental testing and reinforced by numerical simulations, the study examines how varying impact velocities affect the damage patterns in the ceramic layer of the armor. A simplified model of the ceramic damage was created to interpret the fracture patterns observed. It distinguishes between two main zones of damage: the Mescall zone, which contains finer ceramic dust and takes the shape of a truncated cone along the penetration path, and the Macro-cracked zone, characterized by larger, wedge-shaped fragments. The intersection of these zones, known as the hackle zone, defines the different angular geometries of the ceramic damage. The research reveals that the Mescall zone undergoes a rise in stress from compression to a combined tensile-compressive state after the initial shockwave. In contrast, the Macro-cracked zone is dominated by tensile failure due to the primary tensile stress from the impact. Importantly, we found that as the impact velocity increases, the base radius of the Macro-cracked zone's damage cone increases while the height at which the cone crack bifurcates decreases. The size of the Mescall zone's damage cone remains relatively unchanged regardless of the impact velocity. The insights gained from this study are critical for understanding the performance of ceramic/metal composite armor under high-speed impacts and can guide the design of more effective armor systems.</div></div>","PeriodicalId":50318,"journal":{"name":"International Journal of Impact Engineering","volume":"198 ","pages":"Article 105211"},"PeriodicalIF":5.1,"publicationDate":"2024-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143140459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 chemical strengthening, strain rate and stress wave on the flexural properties of aluminosilicate glass","authors":"Bin Jiang ,&nbsp;Liqiang Gao ,&nbsp;Yi Ding ,&nbsp;Jinjin Xu ,&nbsp;Zhen Wang ,&nbsp;Yazhou Guo ,&nbsp;Yulong Li ,&nbsp;Guozhong Gao","doi":"10.1016/j.ijimpeng.2024.105214","DOIUrl":"10.1016/j.ijimpeng.2024.105214","url":null,"abstract":"<div><div>Plate-like glass structures, such as vehicle windshields and building windows, can experience dynamic failure under impact during service. In this article, the flexural properties of annealed and chemically strengthened aluminosilicate glass were investigated. A series of quasi-static, dynamic uniaxial unidirectional and dynamic uniaxial bidirectional tests were conducted on semi-circular bending specimens. The failure characteristics of specimens were observed using a high-speed photographic system and a scanning electron microscope. The effects of chemical strengthening, strain rate and stress wave on the flexural properties were analyzed. The test results indicated that chemical strengthening and strain rate have significant influence on the flexural properties. The relationship between flexural strength, strain rate and chemical strengthening was predicted using an empirical formula. In contrast, the dynamic flexural properties of specimens do not depend on the number of uniaxial stress waves. Specimens can achieve load balance more quickly in bidirectional tests compared to unidirectional loading, enabling acquisition of more valuable data of brittle specimens such as glass.</div></div>","PeriodicalId":50318,"journal":{"name":"International Journal of Impact Engineering","volume":"198 ","pages":"Article 105214"},"PeriodicalIF":5.1,"publicationDate":"2024-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143140460","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental and numerical investigations on EH36 steel plates subjected to quasi-static penetration and repeated dynamic impact loads","authors":"Fan Liu ,&nbsp;Runhua Li ,&nbsp;Nan Su ,&nbsp;Guoqing Feng","doi":"10.1016/j.ijimpeng.2024.105212","DOIUrl":"10.1016/j.ijimpeng.2024.105212","url":null,"abstract":"<div><div>To investigate the differences in structural response of EH36 steel plates under quasi-static penetration and repeated dynamic impact loads, a series of experimental and numerical studies were conducted. An impact test platform was fabricated for both quasi-static and dynamic loading modes. Eight rectangular plates and eight stiffened plates were tested, in which two different contact modes based on the rotation of the indenter were considered. By conducting the uniaxial tensile test and the high strain rate tensile test, the damage model based on the B-W fracture criterion was established. The effect of strain rate was considered, and a calibration approach to improve the sensitivity of mesh size was proposed. Both quasi-static and dynamic numerical analysis agreed well with the test results, and the established finite element analysis approach provided a reliable prediction of structural failure under the impact loads.</div></div>","PeriodicalId":50318,"journal":{"name":"International Journal of Impact Engineering","volume":"198 ","pages":"Article 105212"},"PeriodicalIF":5.1,"publicationDate":"2024-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143140462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Regularization of softening plasticity models for explicit dynamics using a gradient-enhanced modified Johnson–Holmquist model","authors":"Sjard Mathis Rosenbusch ,&nbsp;Daniel Balzani ,&nbsp;Jörg F. Unger","doi":"10.1016/j.ijimpeng.2024.105209","DOIUrl":"10.1016/j.ijimpeng.2024.105209","url":null,"abstract":"<div><div>The behavior of concrete under high strain rates is often described by plasticity models with softening, which is modeled by a reduction of the yield surface as a function of the local equivalent plastic strain. Many of these models are local and therefore produce mesh-dependent results. In this contribution, the gradient-enhancement of such models is investigated to mitigate the mesh-dependency.</div><div>First, the mesh-dependency of these local formulations based on the analysis with a modified JH2 model as a representative for these constitutive formulations is demonstrated using a one-dimensional benchmark example. In the benchmark, the width of the damaged zone decreases upon mesh-refinement and the dissipated plastic energy tends to zero. It is further shown that a significantly small safety factor for the critical time step is needed in order to achieve accurate results for the benchmark example.</div><div>The first investigated gradient-enhancement approach replaces the equivalent local plastic strain with its nonlocal counterpart. The enhancement is based on the inclusion of inertia and damping to the additional Helmholtz equation which enables the use of the central difference method as an explicit solver. This method successfully distributes the damage over several elements, however, the local equivalent plastic strain still localizes into one cell. The inclusion of hardening with respect to the local equivalent plastic strain inhibits the localization and the dissipated plastic energy converges with mesh-refinement.</div><div>This is further confirmed in a two-dimensional wedge-splitting experiment and a four-point bending test where the damage pattern produced by the local model is mesh-dependent as well and the dissipated plastic energy tends to zero with mesh-refinement. The proposed nonlocal model with hardening results in a consistent damage pattern and the dissipated plastic energy converges. Furthermore, the nonlocal model with hardening is less sensitive to time step refinement, such that computational efficiency can be improved compared to the local model.</div><div>The numerical experiments are implemented using the free open source tool FEniCSx and have been made available on Zenodo.</div></div>","PeriodicalId":50318,"journal":{"name":"International Journal of Impact Engineering","volume":"198 ","pages":"Article 105209"},"PeriodicalIF":5.1,"publicationDate":"2024-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143140890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Impact mechanical behavior of the bionic multipiece ceramic panel","authors":"Tianzhen Li ,&nbsp;Jingyu Liu ,&nbsp;Zehua Han ,&nbsp;Shiqiang Li ,&nbsp;Yong Cao ,&nbsp;Zhihua Wang","doi":"10.1016/j.ijimpeng.2024.105210","DOIUrl":"10.1016/j.ijimpeng.2024.105210","url":null,"abstract":"<div><div>Biological protective structures serve as a reference for the design of contemporary impact protection systems. This study introduces an innovative biomimetic design, inspired by the armadillo's carapace, featuring angled alumina ceramic tiles and interlocking multipiece ceramic panels. Ballistic impact tests, conducted at velocities from 150 to 300 m/s, are utilized to evaluate the impact resistance and mechanical behavior of this design. Furthermore, a five-point displacement field inversion strategy is proposed to determine the damage parameters of the JH-2 model, with supplementary parameters derived through extrapolation from experimental data. Simulations using these parameters revealed the defensive mechanisms of the biomimetic panels. The results highlight that these panels can improve impact resistance at comparable thicknesses. The ceramic's substantial ballistic impedance is complemented by the bionic structure's interlocking boundaries, which efficiently dissipate energy and prevent the propagation of circumferential stresses.</div></div>","PeriodicalId":50318,"journal":{"name":"International Journal of Impact Engineering","volume":"198 ","pages":"Article 105210"},"PeriodicalIF":5.1,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143140465","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamic analysis of additively manufactured tensegrity structures","authors":"Keivan Davami ,&nbsp;Russell Rowe ,&nbsp;Ben Gulledge ,&nbsp;Jesse Park ,&nbsp;Ali Beheshti ,&nbsp;Anthony Palazotto ,&nbsp;Fariborz Tavangarian ,&nbsp;Sadie Beck","doi":"10.1016/j.ijimpeng.2024.105208","DOIUrl":"10.1016/j.ijimpeng.2024.105208","url":null,"abstract":"<div><div>Herein, we present an analysis, design, and experimental testing of modular prestressed pin-jointed structures constructed from bistable units and inspired by the classical triangular tensegrity prism. Tensegrity structures, characterized by a combination of tension members (cables) and compression members (bars) in a self-equilibrated state, have gained significant attention in engineering over the past two decades due to their unique nonlinear mechanical behavior. The discontinuity of the compression members in tensegrity structures leads to a slightly different failure behavior compared to their lattice structure counterparts, with unprecedented applications. However, traditional fabrication and assembly methods have posed challenges for their widespread adoption. This research benefits from a recently introduced innovative approach for designing and fabricating bistable “tensegrity-like” units where there exists no flexible element in its structure. Vat photopolymerization technology was utilized to create compliant mechanisms based on a triangular tensegrity prism. Two types of structures, namely a double tensegrity-like unit cell and a lattice structure incorporating the triangular tensegrity prism, were fabricated. Quasi-static compression tests were conducted along with high strain rate experiments were conducted using a specialized direct-impact Hopkinson pressure bar setup. Compression tests at both low and high strain rates confirmed the reliable activation of the designed bistable twisting mechanism, even under large displacements, without the need for self-stress. Experimental results at low and high strain rates demonstrated that these low-density units (designed relative density of 20 %) with bistable characteristics are well-suited for applications requiring highly customizable multistable metamaterials. Here, a sudden transition event (snapping), was clearly seen in both quasi-static and dynamic tests. This, indeed, shifts the structure into a secondary stable configuration while maintaining the twisting mechanism throughout the loading cycles. Overall, this study presents a promising avenue for the design and application of tensegrity-like units in various engineering contexts, demonstrating the effectiveness of tensegrities to carry external loads across a wide range of strain rates.</div></div>","PeriodicalId":50318,"journal":{"name":"International Journal of Impact Engineering","volume":"198 ","pages":"Article 105208"},"PeriodicalIF":5.1,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143140461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The design, modelling and testing of an electric gun load for the study of dynamic material properties","authors":"M.D. Fitzgerald ,&nbsp;J.D. Pecover ,&nbsp;N. Petrinic ,&nbsp;D.E. Eakins","doi":"10.1016/j.ijimpeng.2024.105179","DOIUrl":"10.1016/j.ijimpeng.2024.105179","url":null,"abstract":"<div><div>This work presents the design and testing of an electric gun load intended for characterising the properties of materials under extreme conditions. Projectile launch techniques, such as gas guns and electromagnetic (<strong>EM</strong>) flyer plates, are capable of creating planar, high-pressure shocks across substantial material volumes, resulting in precise equation of state measurements. However, achieving these conditions necessitates specific flyer characteristics: the flyer must maintain near-constant density and velocity across a minimum thickness, in the direction of travel, until reaching the target. This has been achieved in EM flyer plates through sophisticated current pulse shaping (Lemke et al., 2014). This work involved the adaptation of an existing electric gun design to meet these criteria while utilising a relatively simple, fixed rise-time, pulsed-power driver instead. The proposed load achieves this by accelerating a 0.5-mm-thick insulating flyer whilst minimising state change (thus maintaining near-constant density) and eliminating the forces driving the flyer prior to impact by launching it across a stand-off distance (ensuring constant velocity). A combination of our 0D model (Fitzgerald et al., 2023) and a 2D in-house hydrocode were used to determine the optimal thicknesses for its constituent parts: the driving metal foil and plastic flyer. Experimental testing was conducted using a 140 kV electric gun load to validate the model’s predictions and examine the correlation between the shock pulse shape at impact and the stand-off distance from the launch site. The results reveal the optimised load successfully generated a shock pulse in a PMMA target block with a magnitude of 20 GPa for a duration of 1.0<!--> <!-->µs, over region with 10 mm width, and at a 10 cm stand-off from the launch site. This large stand-off distance ensured the flyer was ballistic (constant velocity) on impact and also shielded the diagnostic line of sight from plasma generated on launch, allowing for precise measurements to be made. These outcomes suggest the electric gun technique can now be used to explore dynamic properties of materials using relatively simple pulsed-power devices with a fixed current rise-time.</div></div>","PeriodicalId":50318,"journal":{"name":"International Journal of Impact Engineering","volume":"198 ","pages":"Article 105179"},"PeriodicalIF":5.1,"publicationDate":"2024-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143140463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Size effect of reinforced concrete beams under explosive loadings-An experimental and numerical study","authors":"J.S. Cheng,&nbsp;H.M. Wen,&nbsp;S.T. Cui,&nbsp;Y.L. Zhang","doi":"10.1016/j.ijimpeng.2024.105207","DOIUrl":"10.1016/j.ijimpeng.2024.105207","url":null,"abstract":"<div><div>A combined experimental and numerical study has been carried out herein to investigate the size effect of reinforced concrete (RC) beams under explosive loadings. The RC beam specimens are designed strictly according to geometrically similar scaling law. The damage and failure of the specimens are compared and discussed. The measured dimensionless parameters are statistically analyzed, which can be used to assess the damage of RC beams. Both the experimental and numerical results show that there exists significant size effect on RC beams under explosive loadings with the small-size beams having stronger load bearing capacities and less damages than the medium and large-size beams which have weaker load bearing capacities and suffer more damages. The failure morphologies and values of dimensionless parameters of the RC beams obtained by numerical simulations are found to be in good agreement with the experimental observations. Further analysis reveals that the size effect of RC beams under explosive loadings is due to tensile strain rate effects of concrete.</div></div>","PeriodicalId":50318,"journal":{"name":"International Journal of Impact Engineering","volume":"198 ","pages":"Article 105207"},"PeriodicalIF":5.1,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143140464","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The secondary strain growth phenomenon in elastic plane-strain rings","authors":"J.H. Hu ,&nbsp;Q. Dong ,&nbsp;Y.F. Ren ,&nbsp;R. Zhang ,&nbsp;H. Xu ,&nbsp;Y.J. Deng","doi":"10.1016/j.ijimpeng.2024.105206","DOIUrl":"10.1016/j.ijimpeng.2024.105206","url":null,"abstract":"<div><div>Strain growth is a negative phenomenon in the use of explosion containment vessels. Previous studies mainly focused on the strain growth phenomenon caused by the single bending mode. In this paper, the secondary strain growth phenomenon caused by two bending modes is investigated. To study the strain growth phenomenon attributed to two bending modes, we simplified the explosion containment vessel to a plane-strain ring. The relationship between the thickness-to-radius ratio and preferred bending mode is obtained. The strain growth phenomenon of rings with different thickness-to-radius ratios subjected to the same internal impulse loading is studied through numerical simulations. It is shown that the excitation of two bending modes could lead to the occurrence of secondary strain growth, but it is not a sufficient condition for the secondary strain growth phenomenon. The secondary strain growth exhibits three distinct characteristic phases, namely the breathing vibration phase (Phase I), the regular bending vibration phase (Phase II) and the irregular bending vibration phase (Phase III). Phase I is dominated by the breathing mode response. Phase II is dominated by single bending mode and breathing mode, with only the first strain growth occurring in the ring. Phase III is dominated by two bending modes and breathing mode, and the strain could increase again because of the excitation of the second bending mode, leading to the secondary strain growth phenomenon.</div></div>","PeriodicalId":50318,"journal":{"name":"International Journal of Impact Engineering","volume":"198 ","pages":"Article 105206"},"PeriodicalIF":5.1,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143140468","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 measurement method for specific impulse of underwater pressure pulse based on mass-spring","authors":"Wen Liang ,&nbsp;Zizhen Qi ,&nbsp;Yuwu Zhang ,&nbsp;Minzu Liang ,&nbsp;Xiangcheng Li ,&nbsp;Yuliang Lin","doi":"10.1016/j.ijimpeng.2024.105198","DOIUrl":"10.1016/j.ijimpeng.2024.105198","url":null,"abstract":"<div><div>Achieving the accurate evaluation of underwater explosion power is of great interest to the defense of warship. To address the limitations of traditional electrical sensors, a novel method for measuring the specific impulse of underwater pressure pulses using a mass-spring with constrained boundaries (MSCB) is proposed, wherein the specific impulse is estimated based on the mass of discharged water from MSCB. Experimental study using a modified split Hopkinson pressure bar (SHPB) is conducted to investigate the relationship between specific impulse and the mass of discharged water. Additionally, a verified finite element simulation is employed to predict the dynamic responses of MSCB considering the effects of pressure pulse properties and MSCB structural parameters. The findings reveal that, when subjected to pressure pulse loading, the mass block vibrates non-periodically within the constraint boundaries, with the water discharge mainly occurring during the first vibration cycle. The mass block tends to stay on the back constraint boundary as pressure amplitude and duration time increase. Furthermore, the mass of discharge water with respect to MSCB shows a linear correlation with the specific impulse of the pressure pulse, regardless of the rate at which pressure rise, demonstrating the feasibility of MSCB in measuring the specific impulse of underwater pressure pulse. An increase in either stiffness coefficient or weight of the mass block leads to a decrease in the sensitivity coefficient (ratio of discharge water mass to specific impulse) of MSCB. The proposed method for measuring specific impulse of underwater pressure pulses does not require a power supply and can serve as an important complement to electrical measurements, particularly for testing in extreme underwater explosion environments.</div></div>","PeriodicalId":50318,"journal":{"name":"International Journal of Impact Engineering","volume":"198 ","pages":"Article 105198"},"PeriodicalIF":5.1,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143140467","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}