Forces in mechanics最新文献

{"title":"Numerical and experimental investigation for flexural response of Kevlar short fiber tissue/carbon fiber belts toughened honeycomb sandwich plate","authors":"Rahul Kumar (Research Scholar),&nbsp;Achchhe Lal (Assistant Professor),&nbsp;B.M. Sutaria (Associate Professor)","doi":"10.1016/j.finmec.2023.100222","DOIUrl":"10.1016/j.finmec.2023.100222","url":null,"abstract":"<div><p>This paper investigates the flexural behavior of honeycomb sandwich panels with a toughened/untoughened interface using carbon fiber belt and short aramid fiber tissues. In the first part of the paper, bending response analysis of carbon fiber aluminum honeycomb sandwich plates with an untoughened interface is done using finite element-based first-order shear deformation theory. In the second part, experimental analysis is done to examine the effect of loading rates on the mechanical characteristics of plain and toughened sandwich panels using a three-point bending test. Four types of interface toughening are used as unidirectional and bi-directional stitches of carbon fiber belts, Kevlar short-fiber tissues, and carbon fiber belts combined with Kevlar short-fiber tissues. Experimental result shows that interface toughening improves the maximum load and energy absorbed by sandwich specimens for all loading rates. A scanning electron microscope is used to observe and analyze the failure mode and mechanism of strengthening the interface. It is observed that the stitch of the carbon fiber belt increases the adhesion contact between face sheets and core leading to prevent interfacial debonding. The peak load and energy absorptions of carbon fiber belts toughened interface sandwich are increased by 51 % and 42.5 %, respectively, compared with that of the plain sandwich by a small increment of weight (14%).</p></div>","PeriodicalId":93433,"journal":{"name":"Forces in mechanics","volume":"12 ","pages":"Article 100222"},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44703757","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improvement in asphalt binder rutting performance and fatigue life using electrospun polyacrylonitrile (PAN) nanofibers","authors":"Alberto Gaxiola ,&nbsp;Alexandra Ossa ,&nbsp;Laura González-Maturana ,&nbsp;Omar Llanes-Cárdenas ,&nbsp;M.J. Chinchillas-Chinchillas ,&nbsp;Clemente G. Alvarado-Beltrán ,&nbsp;Andrés Castro-Beltrán","doi":"10.1016/j.finmec.2023.100226","DOIUrl":"10.1016/j.finmec.2023.100226","url":null,"abstract":"<div><p>Recently, high aspect ratio materials like nanofibers with outstanding mechanical properties have been developed and used to improve the mechanical characteristics of construction materials. However, despite the excellent results obtained in asphalt binder modification, only a few types of polymeric nanofibers have been used for this purpose. In this sense, polyacrylonitrile has good thermal and mechanical characteristics to maintain the shape at the typical temperatures the asphalt is heated.</p><p>This study evaluates the effect of electrospun polyacrylonitrile (PAN) nanofibers on the rutting resistance and fatigue parameters of asphalt binders. For this, fibers with an average diameter of 1.3 µm were prepared and randomly dispersed into neat PG 64–22 asphalt binder. Subsequently, a dynamic shear rheometer (DSR) was used to determine <em>G*/sin δ, J_nr, R_3.2</em>, and <em>N_f</em>.</p><p>In the range studied, <em>Jnr_3.2</em> showed a reduction of up to 35%, and the elastic recovery increased up to 4.5 times compared to the reference material. It was observed that the PAN nanofibers increased the fatigue resistance of asphalt binder at temperatures when the material is predominantly viscoelastic. These results show a promising new application of PAN nanofibers to improve the performance of asphalt pavements.</p></div>","PeriodicalId":93433,"journal":{"name":"Forces in mechanics","volume":"12 ","pages":"Article 100226"},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41308942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of chemically reactive squeezing flow of silica and titania hybrid nanoparticles in water-based medium between two parallel plates with higher order slip","authors":"O.A. Famakinwa,&nbsp;O.K. Koriko,&nbsp;K.S. Adegbie","doi":"10.1016/j.finmec.2023.100220","DOIUrl":"10.1016/j.finmec.2023.100220","url":null,"abstract":"<div><p>Considering the significance of hybrid nanofluid over convectional fluid in terms of high rate of heat transfer, nanoscience and nanotechnology has been enhanced by dispersing nanoparticles in the base fluid to obtain new material with series of properties and applications. In this study, the analysis of chemically reactive squeezing flow conveying silica and titanium dioxide nanoparticles in water-based medium across two parallel plates with higher order velocity slip is carried out employing three different chemical kinetics for exothermic/endothermic reactions. The system of partial differential equations resulting from the fluid model assumed the ordinary differential form in alliance with appropriate similarity variables. The modified ordinary differential equations is simulated numerically in MATLAB software package using fourth order Runge–Kutta integration scheme in line with shooting techniques. The tested validity for limited case conform to preceding reports in the literature. The outcomes from the scrutiny uncovered in tables and graphs revealed that the velocity and temperature distributions of the hybrid nanofluid decrease steadily as first order slip factor varies from 0.2 to 1.0 but increase with second order slip factor at all levels of chemical kinetics. Moreover, for exothermic reaction, the rate of heat transfer decreases at the lower plate by <span><math><mrow><mo>−</mo><mn>221.923</mn><mo>%</mo></mrow></math></span> with increasing value of activation energy parameter when <span><math><mrow><mi>m</mi><mo>=</mo><mo>−</mo><mn>2</mn><mo>,</mo><mn>0</mn><mo>,</mo><mn>0.5</mn></mrow></math></span> but converse is the case in endothermic reaction as the rate of heat transfer increases by <span><math><mrow><mn>106.382</mn><mo>%</mo></mrow></math></span>.</p></div>","PeriodicalId":93433,"journal":{"name":"Forces in mechanics","volume":"12 ","pages":"Article 100220"},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43436327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On the mechanics of FG nanobeams: A review with numerical analysis","authors":"Atteshamuddin S. Sayyad ,&nbsp;Lazreg Hadji ,&nbsp;Abdelouahed Tounsi","doi":"10.1016/j.finmec.2023.100219","DOIUrl":"10.1016/j.finmec.2023.100219","url":null,"abstract":"<div><p>Since the classical continuum theories are insufficient to account the small size effects of nanobeams, the nonlocal continuum theories such as Eringen's nonlocal elasticity theory, couple stress theory, strain gradient theory and surface elasticity theory have been proposed by researchers to predict the accurate structural response of isotropic and functionally graded composite nanobeams. This review focuses on research work concerned with analysis of size dependent nanoscale isotropic and functionally graded beams using classical and refined beam theories based on Eringen's nonlocal elasticity theory. The present review article also highlight the possible scope for the future research on nanobeams. In the present study, the authors have developed a new hyperbolic shear deformation theory for the analysis of isotropic and functionally graded nanobeams. The theory satisfy the traction free boundary conditions at the top and the bottom surfaces of the nanobeams. Analytical solutions for the bending, buckling and free vibration analysis of simply-supported nanobeams are obtained using the Navier method. To ensure that the present theory is accurate and valid, the results are compared to previous research.</p></div>","PeriodicalId":93433,"journal":{"name":"Forces in mechanics","volume":"12 ","pages":"Article 100219"},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45411739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evolving geometries, topologies, and apertures in fracture networks: Quantitative insights from lattice modeling","authors":"Bakul Mathur,&nbsp;Rahul Prabhakaran,&nbsp;Daniel Koehn","doi":"10.1016/j.finmec.2023.100197","DOIUrl":"10.1016/j.finmec.2023.100197","url":null,"abstract":"<div><p>Fracture networks are crucial in controlling rock mass permeability. Some of the important features of the fracture networks like the density, interconnectivity, spatial distribution, and fracture apertures determine the success of the subsurface operations. Fracture networks can be studied with analogue studies, physical experiments, and numerical modeling. In this study, we analyse the evolution of a two-dimensional fracture network under gravitational and shear loads using the lattice modeling capabilities of the microstructural modeling environment “Elle”. The simulation cases include varying gravitational loads and Young’s moduli of the formations. The topological progression of the modeled fracture network from isolated to interconnected nodes depicts a realistic network evolution process. The study shows that the rock stiffness exhibits a direct correlation with the number of fractures influencing the average aperture size of the network. A higher gravity load resulted in the development of a sparse fracture network. Stiffer rock models also showed an early onset of fracturing.</p></div>","PeriodicalId":93433,"journal":{"name":"Forces in mechanics","volume":"12 ","pages":"Article 100197"},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45056537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On optimization of heterogeneous materials for enhanced resistance to bulk fracture","authors":"Sukhminder Singh ,&nbsp;Lukas Pflug ,&nbsp;Julia Mergheim ,&nbsp;Michael Stingl","doi":"10.1016/j.finmec.2023.100200","DOIUrl":"10.1016/j.finmec.2023.100200","url":null,"abstract":"<div><p>We propose a novel approach to optimize the design of heterogeneous materials, with the goal of enhancing their effective fracture toughness under mode-I loading. The method employs a Gaussian processes-based Bayesian optimization framework to determine the optimal shapes and locations of stiff elliptical inclusions within a periodic microstructure in two dimensions. To model crack propagation, the phase-field fracture method with an efficient interior-point monolithic solver and adaptive mesh refinement, is used. To account for the high sensitivity of fracture properties to initial crack location with respect to heterogeneities, we consider multiple cases of initial crack and optimize the material for the worst-case scenario. We also impose a minimum clearance constraint between the inclusions to ensure design feasibility. Numerical experiments demonstrate that the method significantly improves the fracture toughness of the material compared to the homogeneous case.</p></div>","PeriodicalId":93433,"journal":{"name":"Forces in mechanics","volume":"12 ","pages":"Article 100200"},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42239057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of static and dynamic responses considering thickness stretching effect for layered composite and sandwich arches using exponential shear and normal deformation theory","authors":"Valmik M. Mahajan ,&nbsp;Amit Sharma","doi":"10.1016/j.finmec.2023.100204","DOIUrl":"10.1016/j.finmec.2023.100204","url":null,"abstract":"<div><p>Present theory investigates the dimensionless vibration frequencies, deformations, and stresses for multilayered and sandwich arches using exponential shear and normal deformation theory (ESNDT). Present studies consider the effect of <span><math><mrow><mo>[</mo><mrow><mn>1</mn><mo>+</mo><mo>(</mo><mrow><mi>z</mi><mo>/</mo><mi>R</mi></mrow><mo>)</mo></mrow><mo>]</mo></mrow></math></span>radius of curvature while selecting the displacement field of arches under the action of uniform load. It includes the effects of transverse shear <span><math><mrow><mo>(</mo><mrow><msub><mi>γ</mi><mrow><mi>x</mi><mi>z</mi></mrow></msub><mo>≠</mo><mn>0</mn></mrow><mo>)</mo></mrow></math></span> and transverse normal deformation<span><math><mrow><mo>(</mo><mrow><msub><mrow><mi>ε</mi></mrow><mi>z</mi></msub><mspace></mspace><mo>≠</mo><mspace></mspace><mn>0</mn></mrow><mo>)</mo></mrow></math></span> <em>i.e.,</em> effect of thickness stretching. The governing relations are obtained using the Navier's method, and Hamilton's virtual work principle. The proposed layered arches are completely free from shear correction, and its top and bottom surfaces is satisfies zero traction free end conditions. Present study obtained very accurate natural frequencies for layered sandwich arches than other theories because, available literature not considered the thickness stretching effect <em>i.e.,</em><span><math><mrow><mo>(</mo><mrow><msub><mrow><mi>ε</mi></mrow><mi>z</mi></msub><mspace></mspace><mo>=</mo><mn>0</mn></mrow><mo>)</mo></mrow></math></span>. Hence, the present scientific investigation accounts the effect of thickness stretching <em>i.e.,</em><span><math><mrow><mo>(</mo><mrow><msub><mrow><mi>ε</mi></mrow><mi>z</mi></msub><mspace></mspace><mo>≠</mo><mspace></mspace><mn>0</mn></mrow><mo>)</mo></mrow></math></span>. However, the non-availability of exact elasticity results of bending and dynamic responses for layered sandwich arches. Present theory is obtained vibration frequencies, displacements, and stresses of layered composite and sandwich arches; the results are compared and validates through prior published literature.</p></div>","PeriodicalId":93433,"journal":{"name":"Forces in mechanics","volume":"12 ","pages":"Article 100204"},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41668572","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comprehensive analysis and economic study of railway brake failure from metal-based and composites-based materials","authors":"Muhammad Akhsin Muflikhun ,&nbsp;Mayradaffa Adyudya ,&nbsp;Nur Fatah Rahman ,&nbsp;Jayan Sentanuhady ,&nbsp;Swathi Naidu Vakamulla Raghu","doi":"10.1016/j.finmec.2023.100223","DOIUrl":"10.1016/j.finmec.2023.100223","url":null,"abstract":"<div><p>The brake system is one of the most critical components in transportation, especially for massive machines such as trains. Brake components decelerate the train by using friction force between the train wheels and the brake block. The efficacy of a brake system strongly depends on the quality of the material components, especially the brake blocks. This study investigated the failure brake block on three different model of brake blocks used in Indonesia (grey cast iron, composite, and magnetic composite). Several characteristics and evaluations are used, i.e., non-destructive surface analysis, microhardness, Energy Dispersive X-Ray (EDX) analysis, and computational Finite Element Method (FEM). The microscopic analysis showed severe conditions at the non-magnetic brake, followed by the magnetic brake. The roughness test indicates that the Ra value for the magnetic brake is higher than the non-magnetic composite brake, with 4.59 and 4.08, respectively. The micro hardness test revealed that in metal-based materials indentation, the results showed magnetic composite has the highest value followed by cast iron and non-magnetic composite with 306, 283, and 218, respectively. In EDX examination, magnetic brakes have filler materials such as Calcium Carbonate and Wollastonite that create better performance. The study showed that the magnetic composite brake blocks demonstrate adequate resistance to failure due to the composite's filler material, which acts as a reinforcing agent.</p></div>","PeriodicalId":93433,"journal":{"name":"Forces in mechanics","volume":"12 ","pages":"Article 100223"},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41848951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Non-local effect of eccentrically simply supported beam on free vibration","authors":"Bojin Li ,&nbsp;Diyun Wen ,&nbsp;Xin-Chun Shang ,&nbsp;Rui Zhang","doi":"10.1016/j.finmec.2023.100218","DOIUrl":"10.1016/j.finmec.2023.100218","url":null,"abstract":"<div><p>Based on the Euler-Bernoulli beam theory, the coupling effect between bending vibration mode shape and longitudinal vibration mode shape of the beam is analyzed when the beam is supported by eccentric simply supported. Under the assumption of small deformation, the vibration control equations and the coupling boundary conditions are obtained through Hamilton's principle and the principle of virtual work variation. The numerical results under three different boundary conditions are given. It shows that the natural frequencies of the beam vary with the eccentricity distances are in complete agreement with the results obtained from finite element analysis and literature. The results strongly proved the validity and correctness of the coupling method in this paper. It also indicates that eccentric simply supported constraints have non-local effects.</p></div>","PeriodicalId":93433,"journal":{"name":"Forces in mechanics","volume":"12 ","pages":"Article 100218"},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42963577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Extending a generic and fast coarse-grained molecular dynamics model to examine the mechanical behavior of grafted polymer nanocomposites","authors":"Maximilian Ries,&nbsp;Sebastian Reber,&nbsp;Paul Steinmann,&nbsp;Sebastian Pfaller","doi":"10.1016/j.finmec.2023.100207","DOIUrl":"10.1016/j.finmec.2023.100207","url":null,"abstract":"<div><p>Polymer nanocomposites are an important class of materials for engineering applications due to their high versatility and good mechanical properties combined with low density. By directly attaching the polymer chains to the nanofillers, the so-called grafting, a better load transfer between matrix and filler is achieved, and, in addition, a better dispersion of the fillers is obtained. Both result in enhanced mechanical properties. Since experimental investigations on the nanoscale are extremely challenging, complementary numerical studies are needed to unravel the mechanical behavior of polymer nanocomposites. To this end, molecular dynamics is ideally suited since it captures the microstructure, but is also numerically expensive. Therefore, this contribution presents a fast coarse-grained molecular dynamics model for the investigation of the mechanical behavior of grafted polymer nanocomposites. For this purpose, we extend an existing model by grafting bonds, which allows us to compare the effect of untreated and grafted fillers directly. In particular, we investigate the influence of filler content, grafting degree, and filler size on the stiffness and strength of the polymer (grafted) nanocomposites. We conclude that the grafting bonds have little effect on the stiffness, while the strength is significantly improved compared to the untreated fillers, which is in agreement with the literature. The presented molecular dynamics model for polymer grafted nanocomposites provides the basis for further investigations, particularly of the crucial matrix-filler interphase. In addition, this contribution translates molecular dynamics insights into mechanical properties, which bridges the gap to the engineering scale and thus represents a step towards exploiting the full potential of polymer (grafted) nanocomposites.</p></div>","PeriodicalId":93433,"journal":{"name":"Forces in mechanics","volume":"12 ","pages":"Article 100207"},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48293648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}