Amir Mousavi , M.R.M. Aliha , Hadi Khoramishad , Hamid Reza Karimi
{"title":"The effect of non-singular term (T-stress) on mode I/III cracking parameters of brittle materials, Numerical and experimental study using different beam and disc shape specimens made of marble rock","authors":"Amir Mousavi , M.R.M. Aliha , Hadi Khoramishad , Hamid Reza Karimi","doi":"10.1016/j.finmec.2024.100303","DOIUrl":"10.1016/j.finmec.2024.100303","url":null,"abstract":"<div><div>This study focuses on less-studied mode I/III fracture cracking behaviour. Seven specimens (ENDC, DNDC, SCB, ENDB, ATPB, TPB-IC, and SENB) were analyzed numerically and experimentally. Results show in pure mode-I, the specimens show identical <em>K</em><sub>Ic</sub> values (1.22 to 1.54 MPa√m). Especially if the <em>K</em><sub>Ic</sub> was measured by compressive specimens (ENDC and DNDC with <em>K</em><sub>Ic</sub> of 1.22 and 1.30 MPa√m, respectively) and was neglected. In these cases, the difference in measured <em>K</em><sub>Ic</sub> values directly relates to the <em>T</em>-stress value in pure mode-I. So, higher T-stress values increase the <em>K</em><sub>Ic</sub> and vice versa. In pure mode-III, which can only simulated by ENDB, ENDC, and DNDC specimens, the difference in measured <em>K</em><sub>IIIc</sub> values was enormous, as 0.99 MPa√m for ENDB, 2.0 MPa√m for ENDC and 2.53 MPa√m for DNDC. Comparing the trend of <em>K</em><sub>IIIc</sub> for specimens shows the same as <em>K</em><sub>Ic</sub>, <em>K</em><sub>IIIc</sub> also has a direct relation with the T-stress. The affectability of fracture toughness from <em>T</em>-stress shows the importance of accounting for it in calculations. The trends show that the ENDB, ENDC, and DNDC specimens have considerably negative <em>T</em>-stress values, with different trends. Moving from pure mode-I to pure mode-III, the ENDB has a low-negative T-stress that becomes high-negative (about -0.32 to -2.5 MPa). Meanwhile, of DNDC, it is the opposite; the T-stress is high-negative for pure mode-I and becomes low-negative for pure mode-III (about -2.54 to -0.77 MPa). For ENDC, the <em>T</em>-stress is almost constant moderate-negative in all the mixed mode I/III conditions (about -2.1 MPa).</div></div>","PeriodicalId":93433,"journal":{"name":"Forces in mechanics","volume":"18 ","pages":"Article 100303"},"PeriodicalIF":3.2,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143129663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Dynamics of nonlocal stress-driven Rayleigh Beam","authors":"D. Indronil","doi":"10.1016/j.finmec.2024.100299","DOIUrl":"10.1016/j.finmec.2024.100299","url":null,"abstract":"<div><div>This paper presents a novel investigation of the dynamic behavior of Rayleigh nanobeams using a nonlocal stress-driven differential elasticity model, extending the foundational work of Barretta. Unlike previous studies that exclusively employed the Euler-Bernoulli beam theory and neglected rotary inertia, this work is the first to incorporate the rotary inertia term within the stress-driven nonlocal framework, providing a more accurate and comprehensive analysis of nanoscale beam dynamics. The equilibrium equations are derived using a variational approach and solved analytically via the Laplace transform technique, yielding closed-form expressions for the natural frequencies of nanobeams under various boundary conditions, including simply supported, clamped, and cantilevered configurations. The results demonstrate that nonlocal stress effects significantly increase the natural frequencies, particularly in higher vibrational modes, where sensitivity to size-dependent interactions is most pronounced. These findings highlight the inadequacy of classical elasticity models and the necessity of accounting for nonlocal and rotary inertia in dynamic analyses. The proposed model shows excellent agreement with existing literature, validating its robustness and offering valuable insights for designing and optimizing nanoscale devices such as MEMS, NEMS, and nanocomposites. This study sets a new benchmark in nonlocal elasticity by addressing rotary inertia, paving the way for more refined studies of nanoscale dynamics.</div></div>","PeriodicalId":93433,"journal":{"name":"Forces in mechanics","volume":"18 ","pages":"Article 100299"},"PeriodicalIF":3.2,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143129660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"An analytical solution for the evaluation of residual stresses in coiling of metal sheets","authors":"D.P. Yesane , R.S. Hingole , R.V. Bhortake","doi":"10.1016/j.finmec.2025.100305","DOIUrl":"10.1016/j.finmec.2025.100305","url":null,"abstract":"<div><div>The coiling process is widely used in the manufacturing industry for the compact storage and transportation of metal sheets. However, this process can induce residual stress in the material, which significantly affects the mechanical properties and performance of the final product. This paper presents a closed-form analytical solution for predicting residual stresses in steel sheets resulting from coiling before cold forming into sections. The study models the coiling process as an elastic-plastic plane-strain pure-bending problem, assuming that the steel obeys the Von Mises yield criterion and the Prandtl-Reuss flow rule. This paper explores the impact of coiling radius and steel yield stress on residual stresses, emphasizing the nonlinear variations in residual stresses across the thickness of steel sheets. The analytical predictions of residual stress were experimentally validated using X-ray diffraction, demonstrating close agreement with the finite element analysis (FEA) results. The impact of coiling radius and yield stress on the final residual stresses was also examined. The developed analytical method provides solutions for developed residual stresses during the coiling of metal sheets with higher accuracy, zero cost, and less time-consuming than current available experimental methods for measuring residual stresses.</div></div>","PeriodicalId":93433,"journal":{"name":"Forces in mechanics","volume":"18 ","pages":"Article 100305"},"PeriodicalIF":3.2,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143129803","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Residual stresses in 4D printed structures: A review on causes, effects, measurements, mitigations and its applications","authors":"Chandramohan Abhishek, Nadimpalli Raghukiran","doi":"10.1016/j.finmec.2024.100304","DOIUrl":"10.1016/j.finmec.2024.100304","url":null,"abstract":"<div><div>3D printing of stimulus responsive materials or smart materials are referred to as 4D printing. The ability of these materials to change their shape or properties over time is considered the fourth dimension. 4D printed parts possess residual stress just as any other manufactured object. Residual stress is that which remains in an object despite the absence of a load. It may develop during the printing process, or post printing. This paper presents an original review on the causes, adverse effects, measurement techniques, and mitigation of residual stresses in 4D printing. A simple sequence for checking the adverse effects of residual stress on 4D printed parts, and applying mitigation techniques is proposed. Building on the review, discussions on original results from design strategy, experimentation, characterization, and finite element analysis were presented. The applications of residual stress mitigation, and the prospects of this work are also discussed.</div></div>","PeriodicalId":93433,"journal":{"name":"Forces in mechanics","volume":"18 ","pages":"Article 100304"},"PeriodicalIF":3.2,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143129662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ayad Mutafi , J.M. Irwan , Noorfaizal Yidris , Abdullah Faisal Alshalif , Yazid Saif , Hamdi Abdulrahman , Ala Mutaafi , Yasser Yahya Al-Ashmori , Mugahed Amran , Nelson Maureira-Carsalade , Siva Avudaiappan
{"title":"Residual stresses in cold-formed steel sections: An overview of influences and measurement techniques","authors":"Ayad Mutafi , J.M. Irwan , Noorfaizal Yidris , Abdullah Faisal Alshalif , Yazid Saif , Hamdi Abdulrahman , Ala Mutaafi , Yasser Yahya Al-Ashmori , Mugahed Amran , Nelson Maureira-Carsalade , Siva Avudaiappan","doi":"10.1016/j.finmec.2025.100306","DOIUrl":"10.1016/j.finmec.2025.100306","url":null,"abstract":"<div><div>Cold-formed steel (CFS) members offer significant advantages over hot-rolled sections, primarily due to their high strength-to-weight ratio and versatility in forming various cross-sectional shapes. These attributes make CFS an efficient choice for design and construction. This paper reviews current design methods for CFS, focusing on the impact of initial imperfections. It also examines various techniques for measuring residual stress in CFS sections, including analytical, experimental, and numerical approaches. The study concludes that while analytical methods are effective, they become complex when accounting for material anisotropy. Laboratory techniques provide reliable measurements but are limited in detecting through-thickness residual stresses. Numerical approaches offer comprehensive insights but require further validation across different material and geometric configurations. The paper highlights the need for advanced analytical models, improved laboratory methods, and expanded numerical techniques to address existing knowledge gaps in residual stress assessment for CFS structures.</div></div>","PeriodicalId":93433,"journal":{"name":"Forces in mechanics","volume":"18 ","pages":"Article 100306"},"PeriodicalIF":3.2,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143129659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Modified CEL method for determination of defect formation mechanism in underwater stationary shoulder FSW based on softened pressure-overclosure contact relationship","authors":"Akbar Hosseini, Alireza Fallahi Arezoudar","doi":"10.1016/j.finmec.2024.100296","DOIUrl":"10.1016/j.finmec.2024.100296","url":null,"abstract":"<div><div>The Coupled Eulerian-Lagrangian (CEL) method was employed to simulate underwater friction stir welding with a stationary shoulder tool (USSFSW). The governing equations in the CEL method were formulated for FSW based on the immersed boundary method. A new softened pressure-overclosure model was introduced to define contact pressure within the overclosure zone, and an initial nodal clearance control method was implemented to prevent the penetration of Eulerian elements into the Lagrangian domain. For modeling the mechanical and thermal interactions between surfaces, the VUINTERACTION subroutine was utilized. The study focused on the defect formation mechanisms during USSFSW, highlighting the roles of material flow velocity and nodal forces. Simulation results demonstrated close alignment with experimental data, revealing three flow paths that developed during the process, merging in the empty area behind the pin and generating upward material flow. Notably, the maximum flow velocity at the boundary of the third and fourth quadrants ranged from 0.189 to 0.495 m/s, while the overall maximum material flow velocity varied from 0.193 to 0.502 m/s. The nodal force was found to vary between 180 and 600 N; notably, when this force dropped below 200 N, the driving force for material flow decreased, resulting in the inability to fill the cavity behind the tool. Conversely, increasing the nodal force enhanced both backward flow (BF) and horizontal flow (HF), promoting higher material extrusion into the cavity. Ultimately, when the flow velocity fell below approximately 0.25 mm/s and the nodal force dropped below about 200 N, cavity defects in USSFSW became inevitable.</div></div>","PeriodicalId":93433,"journal":{"name":"Forces in mechanics","volume":"17 ","pages":"Article 100296"},"PeriodicalIF":3.2,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143134917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Machine learning approach for predicting early-age thermal cracking potential in concrete bridge piers","authors":"Tu Anh Do, Ba-Anh Le","doi":"10.1016/j.finmec.2024.100297","DOIUrl":"10.1016/j.finmec.2024.100297","url":null,"abstract":"<div><div>In concrete construction, early-age thermal cracks in foundations, abutments, piers, and slabs can arise from non-uniform temperature distribution due to heat from cement hydration. These cracks negatively impact the integrity, load-bearing capacity, and service life of the concrete structures. This paper investigates the application of machine learning (ML) models to predict early-age thermal cracking in concrete bridge piers. The study aims to develop models to forecast thermal cracking potential (<em>η<sub>max</sub></em>) and estimate the timing of potential cracking (<em>t</em>) based on a dataset of various cross-sectional bridge piers and typical tropical temperatures. Four ML models—Support Vector Machine (SVM), Extreme Gradient Boosting (XGB), Artificial Neural Network (ANN), and Genetic Programming (GP)—were trained on 759 samples. The dataset, prepared using the EACTSA program, included parameters like cross-sectional dimensions, ambient temperature, and initial concrete temperature, with <em>η<sub>max</sub></em> and <em>t</em> as outputs. Results show that all the ML models achieved high prediction accuracy with R² scores over 0.96. The GP symbolic equations offer transparency and practical implementation. Compared to conventional methods, ML models provide a rapid, effective tool to optimize concrete member dimensions, formwork removal timing, and control concrete temperature, mitigating early-age thermal cracking risk.</div></div>","PeriodicalId":93433,"journal":{"name":"Forces in mechanics","volume":"17 ","pages":"Article 100297"},"PeriodicalIF":3.2,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142748151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Theoretical and numerical stress analysis in the cam of a medium voltage switchgear vacuum circuit breaker supported by image processing of deformation","authors":"Mahmood Matin , Erfan Fatahi , Hossein Darijani , Aram Arjmand","doi":"10.1016/j.finmec.2024.100298","DOIUrl":"10.1016/j.finmec.2024.100298","url":null,"abstract":"<div><div>Vacuum circuit breakers (VCBs) are widely used in the switchgear industry. Over the past decades, leading companies have conducted extensive research and development to optimize the mechanical mechanisms and understand the kinematics and dynamics behavior of VCBs. The mechanical life of these devices is crucial for safety and reliability. This paper investigates an essential component of the VCB mechanism by evaluating the stress in the cam using theoretical and numerical methods. Furthermore, the calculations are supported by examining a deformed cam in a VCB after 2500 cycles. To this end, contact stress equations for the cylindrical part of the cam and its follower were developed. The ABAQUS finite element software was employed with specified contact properties. Additionally, an image of a cam in a VCB after 2500 cycles was processed and compared to other methods. The results demonstrate that the cam exhibited alternating stress values at different local locations at the end of its profile. However, in general, the Von Mises stress increased as the location on the cam progressed from 0° to 240°.</div></div>","PeriodicalId":93433,"journal":{"name":"Forces in mechanics","volume":"17 ","pages":"Article 100298"},"PeriodicalIF":3.2,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142705243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Quasi-static puncture shear loading characteristics of GLARE/nanoclay laminates with various indenters","authors":"Thiyagu Murgaiyan , Vasudevan Alagumalai , Yoganandam Krishnamoorthy , Prem kumar , Arumugaprabu Veerasimman , Sundarakannan Rajendran , Megavannan Mani , Senthilkumar Jadamuni , Vigneshwaran Shanmugam , Oisik Das","doi":"10.1016/j.finmec.2024.100295","DOIUrl":"10.1016/j.finmec.2024.100295","url":null,"abstract":"<div><div>The potential challenge of delamination in fibre–metal laminates highlight the importance of improving interfacial bonding within the laminate. Developing a comprehensive understanding of the nature of this failure is essential for implementing effective mitigation strategies. This study explores fibre metal laminates comprising aluminium sheets and glass/epoxy, with and without the addition of nanoclay at varying weight percentages (0.5, 1, 1.5, and 2 wt.%). Fabrication involved the hand layup method followed by compression moulding, and the laminates were subjected to flexural, inter-laminar shear strength, and quasi-static punch shear tests (QS-PS). Two different indenters, flat and hemispheric, were employed in the QS-PS. Observations from flexural and interlaminar shear strength tests indicated that fibre metal laminate (FML) composites lacking nanoclay exhibit weakened interfacial bonding between aluminium and fibre layers. Notably, at 1.5 wt.% nanoclay, a substantial improvement in interfacial bonding between the fibre and aluminium layers improved the flexural strength (ca. 337 MPa), interfacial shear strength (ca. 16 MPa) and puncture resistance. The puncture failure modes exhibited variability based on the type of the indenter used, whether flat or hemispherical. For FML composites containing 2 wt.% nanoclay, the puncture shear strength differed significantly between the two indenters, measuring approximately 81 MPa under the flat indenter and about 49 MPa under the hemispherical indenter. Additionally, the corresponding energy absorption values were 880 KJ/g and 919 KJ/g for the flat and hemispherical indenters, respectively.</div></div>","PeriodicalId":93433,"journal":{"name":"Forces in mechanics","volume":"17 ","pages":"Article 100295"},"PeriodicalIF":3.2,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142722287","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ali Mottaghi , Ali Mokhtarian , Mohammad Hashemian , Mostafa Pirmoradian , Soheil Salahshour
{"title":"Free vibration analysis of a functionally graded porous nanoplate in a hygrothermal environment resting on an elastic foundation","authors":"Ali Mottaghi , Ali Mokhtarian , Mohammad Hashemian , Mostafa Pirmoradian , Soheil Salahshour","doi":"10.1016/j.finmec.2024.100294","DOIUrl":"10.1016/j.finmec.2024.100294","url":null,"abstract":"<div><div>This research investigates the free vibrational behavior of a functionally graded porous (FGP) nanoplate resting on an elastic Pasternak foundation in a hygrothermal environment. The nanoplate is modeled based on the nonlocal strain gradient theory (NSGT) and considering several plate theories including the CPT (classical plate theory), the FSDT (first-order shear deformation theory), and the TSDT (third-order shear deformation theory). Several patterns are investigated for the dispersion of pores, and the surface effects are incorporated to enhance the precision of the model. The governing equations and boundary conditions are derived via Hamilton's principle and an exact solution is provided via the Navier method. The impacts of several parameters on the natural frequencies are inspected such as length scale and nonlocal parameters, surface effects, porosity parameter, hygrothermal environment, and coefficients of the foundation. The results show that the impact of the porosity parameter on the natural frequencies of nanoplates is significantly dependent on the porosity distribution pattern. It is discovered that by increasing the porosity parameter from 0 to 0.6, the relative changes of natural frequencies vary from a decrease of 30 % to an increase of 6 %.</div></div>","PeriodicalId":93433,"journal":{"name":"Forces in mechanics","volume":"17 ","pages":"Article 100294"},"PeriodicalIF":3.2,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142705242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}