International Journal of Mechanical Sciences最新文献_第3页

In-plane mechanical behavior of tri-chiral and anti-trichiral auxetic cellular structures

IF 7.1 1区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Mechanical Sciences

Pub Date : 2025-02-21 DOI: 10.1016/j.ijmecsci.2025.110054

Anurag Gupta, Shubham Sharma, Rohit Raju Madke, Rajib Chowdhury

Auxetic cellular structures, characterized by their counterintuitive negative Poisson’s ratio (NPR), have attracted significant attention due to their unique mechanical properties. Their potential for improved energy absorption capabilities makes them promising candidates for applications requiring enhanced resistance to compressive forces. This paper investigates the mechanical response of a specific class of auxetic cellular structures known as chiral auxetics under quasi-static in-plane compressive loading. The study focuses on two distinct chiral structures: tri-chiral and anti-trichiral. A numerical simulation is conducted to evaluate their energy absorption capacities. Numerical results are validated by conducting quasi-static compressive testing of tri-chiral and anti-trichiral auxetic cellular structures fabricated through fused deposition modeling (FDM) 3D printing technique by tuning the printing parameters using Taguchi’s design of experiment approach. Furthermore, parametric investigations are performed to examine the effect of circular node radius and ligament thickness on their energy absorption capacity. The results confirm that tri-chiral auxetic structures shows better energy absorption performance compared to anti-trichiral auxetic structures at the same relative density. The parametric analysis also reveals that variations in node radius and ligament thickness significantly influence the energy absorption performance of these auxetic cellular structures. Finally, the application of tri-chiral auxetics are explored in protective padding structures. The quasi-static experimental testing of the pad structure is conducted to verify the simulated results, while an additional simulation examines localized deformation under constant punching from a rigid hemispherical punch. This incorporation of chiral auxetics in padding structures confirms their applicability in practical applications, demonstrating its potential for broader usage in similar contexts.

{"title":"In-plane mechanical behavior of tri-chiral and anti-trichiral auxetic cellular structures","authors":"Anurag Gupta, Shubham Sharma, Rohit Raju Madke, Rajib Chowdhury","doi":"10.1016/j.ijmecsci.2025.110054","DOIUrl":"10.1016/j.ijmecsci.2025.110054","url":null,"abstract":"<div><div>Auxetic cellular structures, characterized by their counterintuitive negative Poisson’s ratio (NPR), have attracted significant attention due to their unique mechanical properties. Their potential for improved energy absorption capabilities makes them promising candidates for applications requiring enhanced resistance to compressive forces. This paper investigates the mechanical response of a specific class of auxetic cellular structures known as chiral auxetics under quasi-static in-plane compressive loading. The study focuses on two distinct chiral structures: tri-chiral and anti-trichiral. A numerical simulation is conducted to evaluate their energy absorption capacities. Numerical results are validated by conducting quasi-static compressive testing of tri-chiral and anti-trichiral auxetic cellular structures fabricated through fused deposition modeling (FDM) 3D printing technique by tuning the printing parameters using Taguchi’s design of experiment approach. Furthermore, parametric investigations are performed to examine the effect of circular node radius and ligament thickness on their energy absorption capacity. The results confirm that tri-chiral auxetic structures shows better energy absorption performance compared to anti-trichiral auxetic structures at the same relative density. The parametric analysis also reveals that variations in node radius and ligament thickness significantly influence the energy absorption performance of these auxetic cellular structures. Finally, the application of tri-chiral auxetics are explored in protective padding structures. The quasi-static experimental testing of the pad structure is conducted to verify the simulated results, while an additional simulation examines localized deformation under constant punching from a rigid hemispherical punch. This incorporation of chiral auxetics in padding structures confirms their applicability in practical applications, demonstrating its potential for broader usage in similar contexts.</div></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":"289 ","pages":"Article 110054"},"PeriodicalIF":7.1,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143474603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

An improved SPH for simulating SLM process with recoil pressure

IF 7.1 1区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Mechanical Sciences

Pub Date : 2025-02-20 DOI: 10.1016/j.ijmecsci.2025.110060

Ting Long , Keyan Ning

The numerical simulation can predict and analyze the physical phenomena in the selective laser melting (SLM) process, providing reference for the selection of SLM process parameters. The smoothed particle hydrodynamics (SPH) method with high fidelity numerical simulation can be used as a tool to further study the SLM process. In this paper, an improved SPH method is proposed to simulate the molten pool flow in SLM process with recoil pressure caused by metal evaporation. In the improved SPH model, an improved kernel gradient correction (KGC) technique and an improved surface tension model are used to improve the computational accuracy, and a novel heat source applying method is proposed to improve the accuracy of applying the heat source model, and an improved material model are proposed to consider the process of metal evaporation. In the present heat source applying method, an improved method for determining the surface SPH particles interacting with laser is developed and a new ray reflection model is proposed to improve the accuracy of applying the heat source. And the recoil pressure model is applied to model the recoil pressure. The accuracy and effectiveness of the SPH model to simulate SLM process are verified by a series of numerical examples. The results show that the improved SPH model is effective in modeling the molten pool flow under recoil pressure.

{"title":"An improved SPH for simulating SLM process with recoil pressure","authors":"Ting Long , Keyan Ning","doi":"10.1016/j.ijmecsci.2025.110060","DOIUrl":"10.1016/j.ijmecsci.2025.110060","url":null,"abstract":"<div><div>The numerical simulation can predict and analyze the physical phenomena in the selective laser melting (SLM) process, providing reference for the selection of SLM process parameters. The smoothed particle hydrodynamics (SPH) method with high fidelity numerical simulation can be used as a tool to further study the SLM process. In this paper, an improved SPH method is proposed to simulate the molten pool flow in SLM process with recoil pressure caused by metal evaporation. In the improved SPH model, an improved kernel gradient correction (KGC) technique and an improved surface tension model are used to improve the computational accuracy, and a novel heat source applying method is proposed to improve the accuracy of applying the heat source model, and an improved material model are proposed to consider the process of metal evaporation. In the present heat source applying method, an improved method for determining the surface SPH particles interacting with laser is developed and a new ray reflection model is proposed to improve the accuracy of applying the heat source. And the recoil pressure model is applied to model the recoil pressure. The accuracy and effectiveness of the SPH model to simulate SLM process are verified by a series of numerical examples. The results show that the improved SPH model is effective in modeling the molten pool flow under recoil pressure.</div></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":"289 ","pages":"Article 110060"},"PeriodicalIF":7.1,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143453870","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Synergistic interaction of thixotropy and inertia in a C-shaped serpentine channel

IF 7.1 1区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Mechanical Sciences

Pub Date : 2025-02-20 DOI: 10.1016/j.ijmecsci.2025.110068

Seon Yeop Jung , Jun Dong Park , Jo Eun Park , Jaewook Nam , Tae Gon Kang

Thixotropy, a property commonly observed in industrial fluids, significantly influences flow and mixing behavior in micromixers. However, its interaction with fluid inertia remains poorly explored. This study examines the behavior of a thixotropic fluid in a C-shaped serpentine channel, focusing on the complex and poorly understood interaction between thixotropy and inertia. A structure-kinetics model is employed to capture the microstructural changes of the thixotropic fluid. We numerically analyze flow and mixing behavior influenced by the Reynolds and the thixotropy numbers, solving coupled continuity, momentum, and structure evolution equations. Thixotropy has a minimal impact on mixing in the creeping flow regime. In the non-creeping flow regime, however, it enhances rotational flow and mixing by reducing viscosity through structural breakdown and increasing fluid inertia. Our findings demonstrate that in the serpentine channel geometry, thixotropy can enhance mixing performance in shorter channels and with lower energy consumption by interacting synergistically with fluid inertia. This highlights the critical role of rheological properties in the design and operation of micro- and macro-scale mixers, with potential applications in biotechnology, pharmaceuticals, food processing, and manufacturing processes involving thixotropic materials.

{"title":"Synergistic interaction of thixotropy and inertia in a C-shaped serpentine channel","authors":"Seon Yeop Jung , Jun Dong Park , Jo Eun Park , Jaewook Nam , Tae Gon Kang","doi":"10.1016/j.ijmecsci.2025.110068","DOIUrl":"10.1016/j.ijmecsci.2025.110068","url":null,"abstract":"<div><div>Thixotropy, a property commonly observed in industrial fluids, significantly influences flow and mixing behavior in micromixers. However, its interaction with fluid inertia remains poorly explored. This study examines the behavior of a thixotropic fluid in a C-shaped serpentine channel, focusing on the complex and poorly understood interaction between thixotropy and inertia. A structure-kinetics model is employed to capture the microstructural changes of the thixotropic fluid. We numerically analyze flow and mixing behavior influenced by the Reynolds and the thixotropy numbers, solving coupled continuity, momentum, and structure evolution equations. Thixotropy has a minimal impact on mixing in the creeping flow regime. In the non-creeping flow regime, however, it enhances rotational flow and mixing by reducing viscosity through structural breakdown and increasing fluid inertia. Our findings demonstrate that in the serpentine channel geometry, thixotropy can enhance mixing performance in shorter channels and with lower energy consumption by interacting synergistically with fluid inertia. This highlights the critical role of rheological properties in the design and operation of micro- and macro-scale mixers, with potential applications in biotechnology, pharmaceuticals, food processing, and manufacturing processes involving thixotropic materials.</div></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":"289 ","pages":"Article 110068"},"PeriodicalIF":7.1,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143453871","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Constitutive modeling of shear thickening fluid using continuum mechanics

IF 7.1 1区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Mechanical Sciences

Pub Date : 2025-02-20 DOI: 10.1016/j.ijmecsci.2025.110057

Jinyu Yang , Junshuo Zhang , Bochao Wang , Xinglong Gong

Shear thickening fluid (STF) exhibits intelligent rheological properties associated with its strain rates, demonstrating excellent viscosity thickening and thinning effects. These properties effectively enhance the performance of STF utilized in impact protection. However, the thickening effect has posed significant difficulties in the theoretical study of STF, resulting in a lack of specific constitutive models and experimental verification. To address this issue, we perform systematic rheological tests across a wide range of loading rates, thoroughly exploring the intelligent rheological responses of STF. Based on the mechanical behavior, we utilize an innovative approach for STF to develop a novel shear-thickening constitutive model within a framework of continuum mechanics, contributing to its theoretical understanding and providing guidance for applications. Given the nonlinearity of the constitutive equations, we present a corresponding numerical implementation approach to efficiently obtain solutions, and subsequently conduct parameter identification using this approach. The significant overlap between the experimental results and model predictions indicates that the new model accurately captures the intelligent rheological behaviors of STF. Furthermore, we design a series of simulations as anti-impact application scenarios of the STF-based composite, which activates a viscosity thickening effect to deliver strong resistance during high-speed impacts. Interestingly, unlike constant-viscosity materials, the STF-based composite exhibits a unique thinning effect and consumes very little energy during low-speed impacts. Consequently, when used as wearable equipment, it not only effectively weakens high-speed impacts, but also facilitates unrestricted movement during low-speed activities. These findings offer valuable guidance for the designs and applications of STF-based products.

{"title":"Constitutive modeling of shear thickening fluid using continuum mechanics","authors":"Jinyu Yang , Junshuo Zhang , Bochao Wang , Xinglong Gong","doi":"10.1016/j.ijmecsci.2025.110057","DOIUrl":"10.1016/j.ijmecsci.2025.110057","url":null,"abstract":"<div><div>Shear thickening fluid (STF) exhibits intelligent rheological properties associated with its strain rates, demonstrating excellent viscosity thickening and thinning effects. These properties effectively enhance the performance of STF utilized in impact protection. However, the thickening effect has posed significant difficulties in the theoretical study of STF, resulting in a lack of specific constitutive models and experimental verification. To address this issue, we perform systematic rheological tests across a wide range of loading rates, thoroughly exploring the intelligent rheological responses of STF. Based on the mechanical behavior, we utilize an innovative approach for STF to develop a novel shear-thickening constitutive model within a framework of continuum mechanics, contributing to its theoretical understanding and providing guidance for applications. Given the nonlinearity of the constitutive equations, we present a corresponding numerical implementation approach to efficiently obtain solutions, and subsequently conduct parameter identification using this approach. The significant overlap between the experimental results and model predictions indicates that the new model accurately captures the intelligent rheological behaviors of STF. Furthermore, we design a series of simulations as anti-impact application scenarios of the STF-based composite, which activates a viscosity thickening effect to deliver strong resistance during high-speed impacts. Interestingly, unlike constant-viscosity materials, the STF-based composite exhibits a unique thinning effect and consumes very little energy during low-speed impacts. Consequently, when used as wearable equipment, it not only effectively weakens high-speed impacts, but also facilitates unrestricted movement during low-speed activities. These findings offer valuable guidance for the designs and applications of STF-based products.</div></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":"289 ","pages":"Article 110057"},"PeriodicalIF":7.1,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143464003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Phase-field simulation on grain-size dependent fracture of cyclically loaded NiTi-SMA

IF 7.1 1区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Mechanical Sciences

Pub Date : 2025-02-20 DOI: 10.1016/j.ijmecsci.2025.110041

Junyuan Xiong , Bo Xu , Jiachen Hu , Guozheng Kang

Based on crystal plasticity theory, a new non-isothermal fracture phase field model was proposed, incorporating various inelastic deformation mechanisms in NiTi shape memory alloy (SMA). The crack propagation of NiTi-SMA under cyclic loading was simulated by addressing its one-way shape memory effect (OWSME) and super-elasticity (SE). The effects of stress-induced martensite transformation (MT), temperature-induced MT, martensite reorientation (MR), and plastic deformation on the crack propagation of NiTi-SMA were examined. The simulated results indicate that dissipation caused by MT, MR, and plastic deformation effectively reduces the crack propagation rate. The fracture mode (crack propagation path) of NiTi-SMA is strongly correlated with the distribution of grain boundaries. As the grain size increases, the crack propagation rate in the super-elastic NiTi systems increases, and the fracture mode gradually transitions from the transgranular fracture to the intergranular one. However, the crack propagation path in the OWSME NiTi system exhibits independence on grain size, and the crack propagation rate within the OWSME system is slightly lower than that in the SE system. The difference of fracture behavior between the super-elastic NiTi system and shape memory NiTi system can be explained from the perspective of microstructure evolution.

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引用次数: 0

Investigation on the hysteresis behavior of a quarter-wavelength standing-wave thermoacoustic engine

IF 7.1 1区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Mechanical Sciences

Pub Date : 2025-02-19 DOI: 10.1016/j.ijmecsci.2025.110084

Kai Wang , Shancheng Tao , Zhaoyu Li , Xinyan Li , Lihua Tang , Geng Chen

Like many nonlinear dynamical systems, thermoacoustic engines (TAEs) exhibit hysteresis behavior in the amplitude of self-excited acoustic oscillations when the temperature gradient implemented across the porous material is first increased and then decreased gradually. This research studies the hysteresis of a quarter-wavelength standing-wave TAE that relies on a parallel plate stack to realize thermal-acoustic energy conversion. Computational fluid dynamics (CFD) is first employed to investigate the influence of stack parameters, such as stack gap and position, on the hysteresis behavior of the TAE. Following this, in analogy with the modeling of Rijke tubes, a simplified mathematical model of the TAE is developed to provide a qualitative interpretation of the hysteresis curves obtained from the CFD simulations. Finally, experimental tests are conducted to validate the presence of hysteresis in the TAE. Results show that in the bistable zone, the dynamic behavior of the TAE can be either linearly stable fixed points or limit cycles. An external pressure disturbance or energy sink can be applied to alter the dynamics of the TAE. There exist optimal values for the stack gap and position at which the lower and upper critical temperatures, as well as their difference, are minimized. At the optimal stack gap, the pressure amplitude reaches its minimum. However, as the stack is shifted toward the open end, the pressure amplitude gradually decreases, highlighting a trade-off between reducing the onset temperature difference and improving acoustic power generation. The present study gives deeper insights into the hysteresis phenomena reported in previous experimental studies, providing useful guidelines for reducing the critical temperature gradients for the excitation of acoustic oscillations in TAEs.

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引用次数: 0

Scaling effect of impact response for CFST components

IF 7.1 1区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Mechanical Sciences

Pub Date : 2025-02-19 DOI: 10.1016/j.ijmecsci.2025.110051

Liu Jin, Qian Fu, Renbo Zhang, Jian Li, Xiuli Du

The plastic deformation and the strain rate effect caused by the dynamic impact load may cause the classical similarity law to no longer apply to the mutual derivation of the impact resistance between the geometrically similar concrete-filled steel tube (CFST) components. In this study, four CFST components with similar geometric sizes were designed. The effect of component size on the impact response indexes, such as impact displacement, impact force, and energy absorption of geometrically similar CFST components, was studied. It is concluded that the above impact response indexes of geometrically similar CFST components do not fully conform to the classical similarity law; that is, they have a scaling effect. The scaling effect of impact displacement is mainly due to the severe plastic deflection deformation in the mid-span impacted area of large-size CFST components. The scaling effect of impact force is primarily due to the slight normalized contact stiffness in the mid-span impacted area and the severe global stiffness degradation of the large-size CFST components. The scaling effects of the relevant impact response indexes studied in this paper are related to severe plastic deformation and minor contact stiffness of large-size components, and their scaling effect is more significant with the increasing scale factor, which is consistent with those for steel tube and reinforced concrete components. In addition, based on the simulation results and drawing on the classical similarity law expression, the scaling effect model of displacement and impact force for geometrically similar CFST components is preliminarily established, which can predict the calculated scale factor of impact response for CFST components.

{"title":"Scaling effect of impact response for CFST components","authors":"Liu Jin, Qian Fu, Renbo Zhang, Jian Li, Xiuli Du","doi":"10.1016/j.ijmecsci.2025.110051","DOIUrl":"10.1016/j.ijmecsci.2025.110051","url":null,"abstract":"<div><div>The plastic deformation and the strain rate effect caused by the dynamic impact load may cause the classical similarity law to no longer apply to the mutual derivation of the impact resistance between the geometrically similar concrete-filled steel tube (CFST) components. In this study, four CFST components with similar geometric sizes were designed. The effect of component size on the impact response indexes, such as impact displacement, impact force, and energy absorption of geometrically similar CFST components, was studied. It is concluded that the above impact response indexes of geometrically similar CFST components do not fully conform to the classical similarity law; that is, they have a scaling effect. The scaling effect of impact displacement is mainly due to the severe plastic deflection deformation in the mid-span impacted area of large-size CFST components. The scaling effect of impact force is primarily due to the slight normalized contact stiffness in the mid-span impacted area and the severe global stiffness degradation of the large-size CFST components. The scaling effects of the relevant impact response indexes studied in this paper are related to severe plastic deformation and minor contact stiffness of large-size components, and their scaling effect is more significant with the increasing scale factor, which is consistent with those for steel tube and reinforced concrete components. In addition, based on the simulation results and drawing on the classical similarity law expression, the scaling effect model of displacement and impact force for geometrically similar CFST components is preliminarily established, which can predict the calculated scale factor of impact response for CFST components.</div></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":"289 ","pages":"Article 110051"},"PeriodicalIF":7.1,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143480562","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Vibro-acoustic Helmholtz absorber with soft wall for broadband sound absorption

IF 7.1 1区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Mechanical Sciences

Pub Date : 2025-02-18 DOI: 10.1016/j.ijmecsci.2025.110083

Xiaoli Liu , Jiu Hui Wu , Jiamin Niu , Wei Li , Chongrui Liu

Aiming at the issue of low-frequency broadband sound absorption, integrating soft materials into acoustic metamaterials offers a promising method to enhance absorption performance. In this paper, a soft-wall vibro-acoustic Helmholtz metamaterial (SVHM) is presented to achieve low-frequency broadband sound absorption, consisting of two parallel Helmholtz resonators (HRs) and a shared vibro-acoustic plate as the soft boundary. Introducing the soft plate not only couples its multiple vibration modes with the neck hole generating additional resonance peaks, but also enhances the energy dissipation of the original HR structure, thereby improving the sound absorption performance of the SVHM structure compared to HRs of the same thickness. A sample with an average absorption coefficient of 0.83 in the range of 306 Hz - 1188 Hz was designed, and the absorption bandwidth was broadened compared with the corresponding rigid sample of the same size. This SVHM structure could have potential applications in architectural acoustics, mechanical equipment, and transportation noise reduction.

{"title":"Vibro-acoustic Helmholtz absorber with soft wall for broadband sound absorption","authors":"Xiaoli Liu , Jiu Hui Wu , Jiamin Niu , Wei Li , Chongrui Liu","doi":"10.1016/j.ijmecsci.2025.110083","DOIUrl":"10.1016/j.ijmecsci.2025.110083","url":null,"abstract":"<div><div>Aiming at the issue of low-frequency broadband sound absorption, integrating soft materials into acoustic metamaterials offers a promising method to enhance absorption performance. In this paper, a soft-wall vibro-acoustic Helmholtz metamaterial (SVHM) is presented to achieve low-frequency broadband sound absorption, consisting of two parallel Helmholtz resonators (HRs) and a shared vibro-acoustic plate as the soft boundary. Introducing the soft plate not only couples its multiple vibration modes with the neck hole generating additional resonance peaks, but also enhances the energy dissipation of the original HR structure, thereby improving the sound absorption performance of the SVHM structure compared to HRs of the same thickness. A sample with an average absorption coefficient of 0.83 in the range of 306 Hz - 1188 Hz was designed, and the absorption bandwidth was broadened compared with the corresponding rigid sample of the same size. This SVHM structure could have potential applications in architectural acoustics, mechanical equipment, and transportation noise reduction.</div></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":"289 ","pages":"Article 110083"},"PeriodicalIF":7.1,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143487872","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Blast behaviors of biomechanically inspired helicoidal honeycomb plates

IF 7.1 1区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Mechanical Sciences

Pub Date : 2025-02-18 DOI: 10.1016/j.ijmecsci.2025.110082

Ning Hao , Wangchen Yan , Man Zhou , Peng Wang

Crustaceans in nature exhibit a Bouligand-type helicoidal fiber structure, giving them exceptional damage and impact resistance. Honeycomb plates, known for their lightweight and high strength, are extensively used in aerospace, transportation, and architecture. This study presents a novel biomimetic helicoidal honeycomb plate (HHP) that combines the benefits of both these structures. By varying cell geometries (15, 12.5, 10, and 7.5 mm) and helicoidal angles (0°, 60°, 120°, and 180°), the mechanical response of the HHP to blast loadings is examined. Results indicate that the helicoidal angle significantly improves blast resistance. Specifically, the 180° helicoidal angle with 15 and 12.5 mm cell geometries provides the highest blast resistance, while the 120° angle performs best for 10 mm cells and the 0° angle for 7.5 mm cells. To achieve optimal blast resistance, balancing rigidity and toughness is essential. Increasing the helicoidal angle improves blast resistance, especially in structures with lower rigidity. These insights are crucial for the design of advanced protective structures, offering valuable guidance for blast and impact protection in the fields of protective and safety engineering.

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引用次数: 0

Enhancing piezoelectric energy harvesters with rotating triangular auxetic structures

IF 7.1 1区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Mechanical Sciences

Pub Date : 2025-02-18 DOI: 10.1016/j.ijmecsci.2025.110081

Xiaofan Zhang, Xiaobiao Shan, Guangdong Sui, Chengwei Hou, Xuteng Du, Zhaowei Min, Tao Xie

The development of piezoelectric energy harvesters is currently constrained by factors such as output power, bandwidth, and natural frequency, which limit their capacity to efficiently capture the low-frequency vibrational energy prevalent in the environment. To address these challenges, this paper proposes a novel approach to enhance the performance of piezoelectric energy harvesters by integrating a rotating triangular auxetic structure. A method for analyzing the mechanical performance of the auxetic structure under lateral constraints is introduced, demonstrating that the structure exhibits favorable negative Poisson's ratio characteristics and design flexibility. Furthermore, the auxetic structure is incorporated into a cantilever beam piezoelectric energy harvester to design and fabricate a novel auxetic-enhanced energy harvester (AEH), alongside a plate substrate energy harvester (PEH) for comparison. Finite element method (FEM) simulations and experimental results show that the auxetic structure increases the average stress in the piezoelectric patch, creating a distinct negative Poisson's ratio region. Under varying geometric parameters and unit cell numbers, the proposed AEH outperforms the conventional PEH, with output power improvements ranging from 96.3 % to 266.1 %, and reductions in natural frequency between 15.35 % and 42.65 %. By appropriately selecting geometric parameters, the AEH also broadens the energy harvesting bandwidth. This enhancement makes the AEH particularly well-suited for capturing low-frequency vibrational energy from the environment. The large negative Poisson's ratio of the auxetic structure, as demonstrated in this study, contributes to an increased energy density in the piezoelectric patch.

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引用次数: 0