Forces in mechanics最新文献

{"title":"Experimental and numerical investigation on GFRP- aramid honeycomb sandwich panel under bird impact: Estimation of penetration velocity","authors":"M. Karthick ,&nbsp;R. Santhanakrishnan","doi":"10.1016/j.finmec.2023.100240","DOIUrl":"https://doi.org/10.1016/j.finmec.2023.100240","url":null,"abstract":"<div><p>In order to effectively mitigate the risk of bird strikes, it is imperative that radomes situated in areas prone to such incidents possess the capability to endure the impact loads caused by bird collisions. Additionally, these radomes must maintain their electromagnetic transparency. Therefore, glass fibre reinforced polymer (GFRP) with Nomex honeycomb sandwich material is used for radome structural design. The current research is intended to examine the dynamic behavior of sandwich composite panels in order to determine the penetration velocity by testing them at three distinct bird impact velocities, such as 88 m/s, 135 m/s, and 153 m/s. It is necessary to find the velocity at which the bird will penetrate / rupture the radome for the safety of Antenna / Electronic units mounted behind the radome. Finite element explicit code LS-DYNA simulates all three impacts. Extension of the simulation estimated the threshold bird impact velocity to be 146 m/s at which it penetrates the sandwich panel under fixture-controlled boundary condition.</p></div>","PeriodicalId":93433,"journal":{"name":"Forces in mechanics","volume":"13 ","pages":"Article 100240"},"PeriodicalIF":0.0,"publicationDate":"2023-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49755579","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":"Numerical investigation of sandwich plate in bending by a new inverse shear deformation theory based on finite element analysis","authors":"Dhiraj P. Bhaskar,&nbsp;Santosh V. Bhaskar,&nbsp;Sachin S. Raj,&nbsp;L.S. Dhamande","doi":"10.1016/j.finmec.2023.100238","DOIUrl":"https://doi.org/10.1016/j.finmec.2023.100238","url":null,"abstract":"<div><p>Employing innovative kinematic function, a new inverse trigonometric shear deformation theory (nITSDT), variationally suitable, is developed to acquire pertinent data on the bending of sandwich plates subjected to transverse loads with variable aspect ratios(S). This nITSDT eliminates the need for shear correction factors since the transverse shear stress is directly determined by constitutive relations on the two extreme faces of sandwich plate satisfying the shear stress free surface circumstances. The governing equations and boundary conditions of the nITSDT are obtained by applying the dynamic version of the virtual work principle. For sandwich plates with simplly supports, solution is given by MATLAB code using Finite Element (FE) based on nITSDT. The findings of displacements and stresses are supported by those of more comprehensive theories, and the exact solution serves to highlight the viability of the proposed theory.</p></div>","PeriodicalId":93433,"journal":{"name":"Forces in mechanics","volume":"13 ","pages":"Article 100238"},"PeriodicalIF":0.0,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49759609","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":"Local strain evolution and microstructural characterisation of hydrogen-induced damage at different strain rates in dual phase (DP 780) steel","authors":"Anuranjan Kumar,&nbsp;Surajit Kumar Paul","doi":"10.1016/j.finmec.2023.100237","DOIUrl":"https://doi.org/10.1016/j.finmec.2023.100237","url":null,"abstract":"<div><p>Effect of strain rate on the damage behaviour of hydrogen (H)-charged dual phase (DP 780) steel via the <em>in-situ</em> digital image correlation (DIC) technique is investigated in this work. Since stress concentration sites like notches are common in engineering practice, two types of uniaxial tensile tests have been carried out using smooth and notch tensile specimens for detailed analysis. The study reveals the significance of hydrogen embrittlement in DP 780 steel, as no strain rate effect is observed on the mechanical property in the case of an uncharged smooth tensile specimen. However, a significant effect of strain rate is detected after the H-charging. Hydrogen showed a lesser ability to aid the failure process when the applied strain rate is raised, as it could diffuse over a limited distance during the tensile test. The local axial and width strains, along with necking and fracture strains, are quantified for each specimen to understand the strain rate effect better. A centre-line crack is observed in every H-charged specimen's fracture surface owing to the presence of MnS inclusion in DP steel along the central line and its interaction with the atomic hydrogen. Moreover, the degree of hydrogen embrittlement is substantially higher in the notch tensile specimens than in the smooth ones.</p></div>","PeriodicalId":93433,"journal":{"name":"Forces in mechanics","volume":"13 ","pages":"Article 100237"},"PeriodicalIF":0.0,"publicationDate":"2023-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49752541","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":"Time-dependent creep analysis of ultra-high-temperature functionally graded rotating disks of variable thickness","authors":"Vahid Daghigh ,&nbsp;Hamed Edalati ,&nbsp;Hamid Daghigh ,&nbsp;Davy M. Belk ,&nbsp;Kamran Nikbin","doi":"10.1016/j.finmec.2023.100235","DOIUrl":"https://doi.org/10.1016/j.finmec.2023.100235","url":null,"abstract":"<div><p>Functionally graded materials (FGMs) are high temperature-resistant materials that can simultaneously maintain metallic tenacity and anti-corrosive properties. Nevertheless, using FGMs during a multi-year service life at ultrahigh temperatures is crucial. Hence, the time-dependent creep response of variable-thickness rotating disks made of FGM is investigated. Four different disk profiles of linear, concave, convex, and uniform are considered. The material's creep properties are defined by the Bailey-Norton creep law. Loading is a rotation-based mechanical body force and a uniform temperature throughout the disk. Simultaneous solution of equilibrium, stress-strain, and strain-displacement equations yields a non-homogenous differential equation containing variable and time-dependent coefficients. In an attempt to optimize the computation cost, Bat and Fish algorithms were used to optimize the initial strain presumptions. Semi-analytical solution of this differential equation gives radial and circumferential stress histories and displacement histories. To confirm the solution method, initial thermo-elastic radial stress, and the effective stress history are validated with the existing literature; there is a good agreement between the results. In addition, the finite element software ABAQUS was used to model the FGM disk thermo-elastic behavior, and the result was compared with the semi-analytical solution results. This study emphasizes the significance of accounting for creep effects in the design of FGM rotating disks, as remarkable changes in their displacements and stresses occur over time. This study emphasizes the significance of accounting for creep effects in the design of FGM rotating disks, as notable changes in their displacements and stresses occur over time.</p></div>","PeriodicalId":93433,"journal":{"name":"Forces in mechanics","volume":"13 ","pages":"Article 100235"},"PeriodicalIF":0.0,"publicationDate":"2023-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49755576","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":"Determination of the critical cyclic fracture toughness for the mode II in mixed fracture of structural steels","authors":"S. Belodedenko ,&nbsp;O. Hrechanyі ,&nbsp;T. Vasilchenko ,&nbsp;A. Hrechana ,&nbsp;Y. Izhevskyi","doi":"10.1016/j.finmec.2023.100236","DOIUrl":"https://doi.org/10.1016/j.finmec.2023.100236","url":null,"abstract":"<div><p>The developed method of processing experimental data from tests performed according to the four-point asymmetric bending scheme made it possible to establish the coefficient of proportionality between the modes of failure I and II, which for structural steels is in the range of 2,5÷3<em>.</em> The established longevity before the appearance of the critical speed according to the developed models is within the limits of the natural dispersion inherent in fatigue failure, which indicates the effectiveness of the developed algorithm and the correctness of the determined indicators of resistance to failure. The problem of the appearance of an oblique crack during tests on four-point asymmetric bending has been solved. It can be assumed that about 90% of the growth of an oblique crack is caused by the contribution of the mode of failure II.</p></div>","PeriodicalId":93433,"journal":{"name":"Forces in mechanics","volume":"13 ","pages":"Article 100236"},"PeriodicalIF":0.0,"publicationDate":"2023-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49752359","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":"Comparison of the stress intensity factor for a longitudinal crack in an elliptical base gas pipe, using FEM vs. DCT methods","authors":"Luis Espinoza ,&nbsp;Jose Antonio Bea ,&nbsp;Sourojeet Chakraborty ,&nbsp;Daniela Galatro","doi":"10.1016/j.finmec.2023.100233","DOIUrl":"10.1016/j.finmec.2023.100233","url":null,"abstract":"<div><p>While several theoretical and experimental studies for cracks in piping exist, most pertain to pipelines, equipment, or fittings under pressure conditions or under stress corrosion conditions at welding. Element finite Method models have occasionally supplemented experimental methods, to investigate such operational fails. In this approach we explore technical options to comprehensively understand crack propagations, by first, evaluating the Stress Intensity Factor <span><math><mrow><mo>(</mo><msub><mi>K</mi><mi>I</mi></msub><mo>)</mo></mrow></math></span> using ANSYS Parametric design language then, comparing with the Displacement Correlation Technique, for an elliptical base gas piping (20″APL Gr. B) suffering a longitudinal welding-induced crack, under a compression of 1.86 MPa. The <span><math><mrow><msub><mi>K</mi><mi>I</mi></msub><mspace></mspace></mrow></math></span>value for an Electric Resistance Welding crack was calculated for the two-dimensional plane, for a quarter-length of propagated crack along the elliptical front. The <span><math><msub><mi>K</mi><mi>I</mi></msub></math></span> value estimates are 0.94x<span><math><msup><mrow><mo>(</mo><mn>10</mn><mo>)</mo></mrow><mrow><mo>−</mo><mn>3</mn></mrow></msup></math></span> MPa<span><math><msqrt><mi>m</mi></msqrt></math></span> from ANSYS Parametric design language vs. 0.7<span><math><mrow><mn>0</mn><mi>x</mi><msup><mrow><mo>(</mo><mn>10</mn><mo>)</mo></mrow><mrow><mo>−</mo><mn>2</mn></mrow></msup></mrow></math></span> MPa<span><math><mrow><msqrt><mi>m</mi></msqrt><mspace></mspace></mrow></math></span>from DCT the two methods are close less than 1. These results were compared with the theorical stress intensity factor for elliptical cracks by Broek<span>¹</span> David called elementary engineering fracture mechanics where the values were 0.5x<span><math><msup><mrow><mo>(</mo><mn>10</mn><mo>)</mo></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></math></span> MPa<span><math><msqrt><mi>m</mi></msqrt></math></span>. We found that the proposed FEM method for estimating <span><math><mrow><mo>(</mo><msub><mi>K</mi><mi>I</mi></msub><mo>)</mo></mrow></math></span>is the approach that is closest to the theoretical value.</p></div>","PeriodicalId":93433,"journal":{"name":"Forces in mechanics","volume":"13 ","pages":"Article 100233"},"PeriodicalIF":0.0,"publicationDate":"2023-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48174316","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":"Effect of laser peening without coating (LPwC) on retardation of fatigue crack growth in SM490 plates","authors":"Tomoharu Kato ,&nbsp;Yoshihiro Sakino ,&nbsp;Yuji Sano","doi":"10.1016/j.finmec.2023.100234","DOIUrl":"10.1016/j.finmec.2023.100234","url":null,"abstract":"<div><p>Laser peening without coating (LPwC) is a well-known technique to improve high-cycle fatigue properties by introducing compressive residual stress (RS) near the surface of metal components. In this study, X-ray diffraction (XRD) and flexural fatigue tests were applied to pre-cracked 12 mm thick SM490A welding structural steel specimens that were subjected to LPwC nearly 20 years ago with a pulse energy of 200 mJ, a spot diameter of 0.8 mm and a pulse density of 36 pulse/mm². XRD revealed that the compressive RS has remained stable to date, with approximately 400–500 MPa remaining at the surface and a compressive depth of approximately 0.9 mm from the surface, which is comparable to the data measured by XRD immediately after LPwC. In the flexural fatigue tests with a stress ratio of 0.1 and stress rages of 100, 150 and 200 MPa, LPwC extended the fatigue life by more than 1.6 times, depending on the stress range and individual specimens. Crack restarting cycles were significantly increased by a factor of at least 1.8, and the crack growth rate was suppressed by a factor of about 0.7 or less.</p></div>","PeriodicalId":93433,"journal":{"name":"Forces in mechanics","volume":"13 ","pages":"Article 100234"},"PeriodicalIF":0.0,"publicationDate":"2023-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49493862","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":"An improved MITC3 element for vibration response analysis of piezoelectric functionally graded porous plates","authors":"Ngoc-Tu Do ,&nbsp;Trung Thanh Tran ,&nbsp;Trung Nguyen-Thoi ,&nbsp;Quoc Hoa Pham","doi":"10.1016/j.finmec.2023.100231","DOIUrl":"10.1016/j.finmec.2023.100231","url":null,"abstract":"<div><p>The main goal of this paper is to improve the mixed interpolation of tensorial components triangular (MITC3) by using the edge-based smoothed finite element method (ES-FEM), so-called ES-MITC3, for analyzing the vibration of piezoelectric functionally graded porous (p-FGP) plates subjected to dynamic loading. The material properties of the FGP core vary through thickness with uneven porosity distribution. Besides, the linear relationship between the electric potential and the thickness of the piezoelectric sublayer is taken into account. A closed-loop control algorithm is employed to actively control the vibration of p-FGP plates, through feedback from displacement and velocity. The performance of the proposed method is verified through comparative examples. Finally, the authors hope that the present method can be effectively applied to many smart material models in a multiphysics environment and contribute to understanding texture control by piezoelectric materials through numerical results.</p></div>","PeriodicalId":93433,"journal":{"name":"Forces in mechanics","volume":"13 ","pages":"Article 100231"},"PeriodicalIF":0.0,"publicationDate":"2023-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48169622","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":"Ballistic performance of optimised light weight composite armour","authors":"Amar Prakash,&nbsp;M. Fasil,&nbsp;N. Anandavalli","doi":"10.1016/j.finmec.2023.100216","DOIUrl":"10.1016/j.finmec.2023.100216","url":null,"abstract":"<div><p>This research paper presents a comprehensive investigation into the response of a 3D finite element model when subjected to 7.62 AP projectiles. The study utilises Hetherington's armour composite equation and incorporates the Johnson-Holmquist material model to analyse the strength and failure criteria of the ceramic and Kevlar/epoxy components, respectively. The results highlight the remarkable resilience of the composite armour, demonstrating its ability to withstand projectile velocities up to 1500 m/s. However, as the ballistic velocity limit increases, the armour experiences significant damage, including projectile erosion and panel delamination. Through numerical simulations and advanced modelling techniques, the paper thoroughly explores the failure modes and energy absorption characteristics of composite armour systems under projectile impact. It investigates key parameters such as velocity, acceleration, kinetic energy, internal energy, pressure distribution, displacement, and damage progression. The analysis reveals a progressive decrease in kinetic energy as the projectile interacts with the armour, underscoring the crucial role of energy absorption in preventing projectile penetration. Moreover, the impact velocity influences the distribution of internal energy within the composite armour, with higher velocities leading to greater energy absorption up to a threshold limit. The study also determines the ballistic limit velocity (V50) using the velocity history approach and validates the findings with existing literature. Overall, the research provides valuable insights into the limitations of composite armour and offers important recommendations for designing and improving materials to achieve superior ballistic protection. It emphasises the significance of reaching the maximum ballistic limit while maintaining a lightweight armour structure by optimising the total armour thickness. This study contributes to the advancement of armour technology and enhances our understanding of the behaviour of composite materials under high-velocity impacts. It offers valuable guidance for the development of more robust armour systems suitable for various defence and protection applications.</p></div>","PeriodicalId":93433,"journal":{"name":"Forces in mechanics","volume":"12 ","pages":"Article 100216"},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41753914","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":"Radiation force of compressional plane waves on a sphere embedded in an elastic medium†","authors":"F.G. Mitri","doi":"10.1016/j.finmec.2023.100221","DOIUrl":"10.1016/j.finmec.2023.100221","url":null,"abstract":"<div><p>The aim of this work is to derive exact partial-wave series expressions for the radiation force of plane compressional progressive waves propagating inside an elastic medium and incident upon an embedded elastic sphere. The analytical modeling is needed to provide fundamental physical understanding of the underlying phenomenon of mode conversion and its contribution to the acousto-elastic radiation force, and in experimental design. In the context of linear elasticity theory, a rigorous derivation for the acousto-elastic radiation force, based on the integration of the time-averaged radial component of the elastodynamic Poynting vector (or power flow density), is presented and discussed. Initially, the elastic scattering problem is determined and subsequently used to derive the mathematical expression for the acousto-elastic radiation force of progressive compressional waves. The method is also verified using the extended optical theorem for elastic compressional plane waves. Extension to the case of elastic plane standing wave is also provided. Particular importance is made on the contributions of elastic mode preservation (P → P) and mode conversion (P → S) to the acousto-elastic radiation force. Numerical computations for the dimensionless radiation force efficiency and its components demonstrate the importance of compressional-to-shear mode conversion in the scattering by the sphere encased in a linearly-elastic medium. The analytical formalism presented here can be used to validate numerical methods, and the results of the simulations can be utilized as <em>a priori</em> knowledge in optimizing and designing acousto-elastic radiation force experiments involving elastic compressional progressive waves on a sphere in acoustically-engineered materials applications, elasticity imaging methods, activation of implantable devices, characterization of biological tissue, and non-destructive evaluation to name some examples.</p></div>","PeriodicalId":93433,"journal":{"name":"Forces in mechanics","volume":"12 ","pages":"Article 100221"},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46838623","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}