Pub Date : 2025-06-15DOI: 10.1016/j.finmec.2025.100320
Francisco J. Nieves , Ana Bayón , Félix Salazar , Francisco Gascón
The transverse vibration of a bar is studied by applying the Bernoulli-Euler beam theory. The bar is placed between the platens of a hydraulic press that applies compressive stress. When the bar vibrates, its ends slide over the platens with dry friction. Boundary conditions appropriate to the existence of friction are proposed. Once the homogeneous equation of motion is solved analytically, a particular solution is obtained through elementary trigonometric series. The sum of these solutions provides the general solution that shows the movement of all the bar points. The movement is divided into successive stages. The displacement of the bar points as a function of time is calculated numerically. It is demonstrated that there is a sudden change in the shape of vibrating when a specific number of semi-oscillations is reached, going from a behaviour of sliding ends to another of fixed ends. Criteria are proposed to estimate the circumstances in which the partial stop of the vibration occurs, as well as a change in the vibration mode and its frequency.
{"title":"Transverse vibration of an axially compressed bar with dry friction at its ends","authors":"Francisco J. Nieves , Ana Bayón , Félix Salazar , Francisco Gascón","doi":"10.1016/j.finmec.2025.100320","DOIUrl":"10.1016/j.finmec.2025.100320","url":null,"abstract":"<div><div>The transverse vibration of a bar is studied by applying the Bernoulli-Euler beam theory. The bar is placed between the platens of a hydraulic press that applies compressive stress. When the bar vibrates, its ends slide over the platens with dry friction. Boundary conditions appropriate to the existence of friction are proposed. Once the homogeneous equation of motion is solved analytically, a particular solution is obtained through elementary trigonometric series. The sum of these solutions provides the general solution that shows the movement of all the bar points. The movement is divided into successive stages. The displacement of the bar points as a function of time is calculated numerically. It is demonstrated that there is a sudden change in the shape of vibrating when a specific number of semi-oscillations is reached, going from a behaviour of sliding ends to another of fixed ends. Criteria are proposed to estimate the circumstances in which the partial stop of the vibration occurs, as well as a change in the vibration mode and its frequency.</div></div>","PeriodicalId":93433,"journal":{"name":"Forces in mechanics","volume":"20 ","pages":"Article 100320"},"PeriodicalIF":3.2,"publicationDate":"2025-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144338959","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}
Pub Date : 2025-05-01DOI: 10.1016/j.finmec.2025.100314
Hussain Gharehbaghi, Mehdi Aghaei
In this research, the strength analysis and life evaluation of a steam turbine rotor were studied. The effects related to low cycle fatigue and creep were investigated according to ASME BPVC SECTION III-NH. For this purpose, numerical analyses were performed considering transient and steady-state thermal and mechanical loadings. Transient response was used to obtain temperature, stress, and strain distributions as functions of time in low-cycle fatigue analysis, and steady-state response was used for the evaluation of creep effects. Finally, the number of allowed Equivalent Operating Hours (EOH) was determined. Using this method, the turbine start-up curves were modified in such a way that the life provided for the turbine is in the safe area and the fastest possible start-up occurs.
{"title":"Investigation of creep-fatigue interaction in steam turbine rotor","authors":"Hussain Gharehbaghi, Mehdi Aghaei","doi":"10.1016/j.finmec.2025.100314","DOIUrl":"10.1016/j.finmec.2025.100314","url":null,"abstract":"<div><div>In this research, the strength analysis and life evaluation of a steam turbine rotor were studied. The effects related to low cycle fatigue and creep were investigated according to ASME BPVC SECTION III-NH. For this purpose, numerical analyses were performed considering transient and steady-state thermal and mechanical loadings. Transient response was used to obtain temperature, stress, and strain distributions as functions of time in low-cycle fatigue analysis, and steady-state response was used for the evaluation of creep effects. Finally, the number of allowed Equivalent Operating Hours (EOH) was determined. Using this method, the turbine start-up curves were modified in such a way that the life provided for the turbine is in the safe area and the fastest possible start-up occurs.</div></div>","PeriodicalId":93433,"journal":{"name":"Forces in mechanics","volume":"19 ","pages":"Article 100314"},"PeriodicalIF":3.2,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144098817","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}
Pub Date : 2025-05-01DOI: 10.1016/j.finmec.2025.100313
Qiyue Liu , Jintian Liu , Steven Kutschke , Viktoria Kosmalla , David Schürenkamp , Nils Goseberg , Markus Böl
Wave attenuation by vegetation, such as in salt marshes or on coastal dunes, is an environmentally friendly measure for erosion control and coastal protection. A particular factor here is the seasonal variation, both on the plant side and on the wave side. Plants have different mechanical properties and physiology (including morphology, cellular and molecular characteristics) depending on the season. Mechanical experiments are essential to better evaluate the erosion protection provided by coastal vegetation depending on the season, and to generate mechanical properties for corresponding simulations that can predict the vegetation’s resistance to waves, which in turn would enable optimised planting. For this purpose, different bending experiments were performed on salt marsh culm sections collected at different times in the year. Based on the cross-sectional morphology and force–deflection curves, the non-linear structural and material behaviour of the culm section is obtained using the inverse finite element method. The results show that the upper part of the grass culm behaves much more softly than the middle and lower parts, while the culm has a much stiffer material behaviour in winter (March) than in summer (June and September). In addition, this study found a negative correlation between Young’s modulus and second moment of inertia, suggesting an adaptive trade-off between structural and material properties under different growth conditions. The data obtained are important for a general understanding of the seasonal behaviour of salt marsh vegetation. On the other hand, they are particularly valuable for modelling of coastal erosion, vegetation patches or culm-fluid interactions.
{"title":"Seasonal mechanical behaviour of Elymus spec. for the assessment of ecosystem services","authors":"Qiyue Liu , Jintian Liu , Steven Kutschke , Viktoria Kosmalla , David Schürenkamp , Nils Goseberg , Markus Böl","doi":"10.1016/j.finmec.2025.100313","DOIUrl":"10.1016/j.finmec.2025.100313","url":null,"abstract":"<div><div>Wave attenuation by vegetation, such as in salt marshes or on coastal dunes, is an environmentally friendly measure for erosion control and coastal protection. A particular factor here is the seasonal variation, both on the plant side and on the wave side. Plants have different mechanical properties and physiology (including morphology, cellular and molecular characteristics) depending on the season. Mechanical experiments are essential to better evaluate the erosion protection provided by coastal vegetation depending on the season, and to generate mechanical properties for corresponding simulations that can predict the vegetation’s resistance to waves, which in turn would enable optimised planting. For this purpose, different bending experiments were performed on salt marsh culm sections collected at different times in the year. Based on the cross-sectional morphology and force–deflection curves, the non-linear structural and material behaviour of the culm section is obtained using the inverse finite element method. The results show that the upper part of the grass culm behaves much more softly than the middle and lower parts, while the culm has a much stiffer material behaviour in winter (March) than in summer (June and September). In addition, this study found a negative correlation between Young’s modulus and second moment of inertia, suggesting an adaptive trade-off between structural and material properties under different growth conditions. The data obtained are important for a general understanding of the seasonal behaviour of salt marsh vegetation. On the other hand, they are particularly valuable for modelling of coastal erosion, vegetation patches or culm-fluid interactions.</div></div>","PeriodicalId":93433,"journal":{"name":"Forces in mechanics","volume":"19 ","pages":"Article 100313"},"PeriodicalIF":3.2,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143887150","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}
A passive vibration control study has been carried out to understand the nature of fluid structure interaction on control rods. Further to identify the possible ways to preserve the structural integrity by isolating the impact of vibration. In regards, by employing multiple control tubes to assess the characteristics of induced vibration and flow dynamics over a fuel cell structures in different orientation at a subcritical Reynolds number (Re=18,685) has been proposed. An experimental and numerical investigation has been performed to understand the influence of control tubes over the test structure. The computational study has been performed by employing the Large Eddy Simulation technique to estimate the flow characteristics and it dynamics over the test structures. Similarly, the experimental investigation also focussed on understanding nature of control rods subjected fluid flow with an influence of control tubes. In this study nine different cases were taken into consideration for the better understanding on the proposed idea. It is mainly focussed on the amplitude response with respect to the force coefficients. Further, it examines the near wake flow structure, instantaneous flow field, mean flow field, turbulent intensity, vortex length and mean pressure distribution for all the considered cases. The swirling flow is identified to be more significant in the development of sloping three-dimensional flow structures with a low-frequency force coefficient despite the induced high-frequency force coefficient resulted due to the Karman vortices. In addition, the perfectly organized vortices observed for a larger value of wave sharpness reveals a noteworthy influence on the inconsistency in the lift force. Only a minor peak raise in the amplitude response for the case 4 and case 5 is identified. It is because of the control tubes positioned in the upstream condition causes a blockade effect on the excessive forces on the tube structures, and reduces the displacement effects due to the flow impact directly on the control rods structures. At last, the base pressure coefficient is observed to be along with the stagnation point at .
{"title":"Sustainable passive vibration control of fuel cells on fluid structure interaction","authors":"Karthik Selva Kumar Karuppasamy , Brintha Ramachandran , Aruna Devi Karuppasamy , Balaji P․S․ , Krishna Kumar Jaiswal , Sangmesh B","doi":"10.1016/j.finmec.2025.100316","DOIUrl":"10.1016/j.finmec.2025.100316","url":null,"abstract":"<div><div>A passive vibration control study has been carried out to understand the nature of fluid structure interaction on control rods. Further to identify the possible ways to preserve the structural integrity by isolating the impact of vibration. In regards, by employing multiple control tubes to assess the characteristics of induced vibration and flow dynamics over a fuel cell structures in different orientation at a subcritical Reynolds number (<em>Re</em>=18,685) has been proposed. An experimental and numerical investigation has been performed to understand the influence of control tubes over the test structure. The computational study has been performed by employing the Large Eddy Simulation technique to estimate the flow characteristics and it dynamics over the test structures. Similarly, the experimental investigation also focussed on understanding nature of control rods subjected fluid flow with an influence of control tubes. In this study nine different cases were taken into consideration for the better understanding on the proposed idea. It is mainly focussed on the amplitude response with respect to the force coefficients. Further, it examines the near wake flow structure, instantaneous flow field, mean flow field, turbulent intensity, vortex length and mean pressure distribution for all the considered cases. The swirling flow is identified to be more significant in the development of sloping three-dimensional flow structures with a low-frequency force coefficient despite the induced high-frequency force coefficient resulted due to the Karman vortices. In addition, the perfectly organized vortices observed for a larger value of wave sharpness reveals a noteworthy influence on the inconsistency in the lift force. Only a minor peak raise in the amplitude response for the case 4 and case 5 is identified. It is because of the control tubes positioned in the upstream condition causes a blockade effect on the excessive forces on the tube structures, and reduces the displacement effects due to the flow impact directly on the control rods structures. At last, the base pressure coefficient is observed to be <span><math><mrow><mi>c</mi><mi>p</mi><mo>≈</mo><mn>0.96</mn></mrow></math></span> along with the stagnation point at <span><math><mrow><mi>θ</mi><mo>≈</mo><msup><mrow><mn>71</mn></mrow><mn>0</mn></msup></mrow></math></span>.</div></div>","PeriodicalId":93433,"journal":{"name":"Forces in mechanics","volume":"19 ","pages":"Article 100316"},"PeriodicalIF":3.2,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144213466","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}
Pub Date : 2025-03-21DOI: 10.1016/j.finmec.2025.100312
Diem Dang Nguyen , Hien Duy Ta
This study presents the development of the stochastic finite element method (SFEM) to investigate the random free vibrations of beams with three-dimensional (3D) random field of material properties. Material properties, such as mass density and Young's modulus, are modeled as 3D stationary univariate random fields, with their correlations considered in the dynamic analysis. The random material fields are discretized into random variables using the weighted integral method combined with the perturbation technique to obtain a first-order approximation of the eigenvalues of free vibration. Statistical quantities, including mean, variance, and coefficient of variation (COV), of the eigenvalues are derived. Monte Carlo simulations (MCs), based on standard FEM and the spectral representation method for stochastic fields, are employed to validate the SFEM solution. The three-dimensional randomness of material properties significantly affects the random dynamic response of the structure. Results reveal that as the correlation distance increases, the dispersion of the eigenvalues around the expected value also increases. A perfect positive correlation between the 3D random fields of Young's modulus and mass density results in a smaller COV, whereas a perfect negative correlation leads to a larger COV. As the correlation distance approaches infinity, the COV approaches the total standard deviation for a negative correlation, while it becomes negligible for a positive correlation. For independent random fields, the COV converges to approximately 70 % of the total standard deviation. The nearly linear relationship between COV and standard deviation enables the prediction of the random response of the structure once the material property randomness is defined.
本文介绍了随机有限元法（SFEM）的发展，用于研究具有材料特性三维随机场的梁的随机自由振动。材料性能，如质量密度和杨氏模量，被建模为三维平稳的单变量随机场，并在动态分析中考虑它们的相关性。采用加权积分法结合微扰技术将随机材料场离散为随机变量，得到自由振动特征值的一阶近似。导出了特征值的统计量，包括平均值、方差和变异系数。采用蒙特卡罗模拟（Monte Carlo simulation, MCs），基于标准有限元法和随机场谱表示法，对SFEM解进行了验证。材料性能的三维随机性对结构的随机动力响应有显著影响。结果表明，随着相关距离的增大，特征值在期望值周围的离散度也增大。三维随机场的杨氏模量与质量密度的正相关关系导致COV减小，负相关关系导致COV增大。当相关距离趋近于无穷大时，对于负相关，COV趋近于总标准差，而对于正相关，COV变得可以忽略不计。对于独立随机场，COV收敛到总标准差的约70%。COV与标准差之间的近似线性关系可以在确定材料特性随机性后预测结构的随机响应。
{"title":"Free vibration of beams using stochastic finite element method considering three-dimensional randomness of material properties","authors":"Diem Dang Nguyen , Hien Duy Ta","doi":"10.1016/j.finmec.2025.100312","DOIUrl":"10.1016/j.finmec.2025.100312","url":null,"abstract":"<div><div>This study presents the development of the stochastic finite element method (SFEM) to investigate the random free vibrations of beams with three-dimensional (3D) random field of material properties. Material properties, such as mass density and Young's modulus, are modeled as 3D stationary univariate random fields, with their correlations considered in the dynamic analysis. The random material fields are discretized into random variables using the weighted integral method combined with the perturbation technique to obtain a first-order approximation of the eigenvalues of free vibration. Statistical quantities, including mean, variance, and coefficient of variation (COV), of the eigenvalues are derived. Monte Carlo simulations (MCs), based on standard FEM and the spectral representation method for stochastic fields, are employed to validate the SFEM solution. The three-dimensional randomness of material properties significantly affects the random dynamic response of the structure. Results reveal that as the correlation distance increases, the dispersion of the eigenvalues around the expected value also increases. A perfect positive correlation between the 3D random fields of Young's modulus and mass density results in a smaller COV, whereas a perfect negative correlation leads to a larger COV. As the correlation distance approaches infinity, the COV approaches the total standard deviation for a negative correlation, while it becomes negligible for a positive correlation. For independent random fields, the COV converges to approximately 70 % of the total standard deviation. The nearly linear relationship between COV and standard deviation enables the prediction of the random response of the structure once the material property randomness is defined.</div></div>","PeriodicalId":93433,"journal":{"name":"Forces in mechanics","volume":"19 ","pages":"Article 100312"},"PeriodicalIF":3.2,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143735026","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}
Pub Date : 2025-03-11DOI: 10.1016/j.finmec.2025.100311
Pouya Towhidi, Manouchehr Salehi
It is well known that coupling atomistic and continuum domains introduces inconsistencies near the interface. These inconsistencies manifest as nonphysical forces, known as “ghost forces,” which can lead to significant errors in the solution. In this paper, we propose a novel approach to achieve a consistent atomistic-continuum interface for the quasicontinuum method, applicable to two-body potentials with unlimited range of interaction. To this end, artificial nodes and elements are introduced located at specified positions, and appropriate constraints are applied. We show that in this way, not only ghost forces are eliminated but also the energy remains compatible through the interface. The method is applied to model surface effect and void defect in static problems, as well as to simulate wave propagation. The results demonstrate that the approach substantially improves accuracy in both static and dynamic problems.
{"title":"A closed-form energy expression ensuring consistency in the atomistic-continuum coupling: A one-dimensional atomic chain study","authors":"Pouya Towhidi, Manouchehr Salehi","doi":"10.1016/j.finmec.2025.100311","DOIUrl":"10.1016/j.finmec.2025.100311","url":null,"abstract":"<div><div>It is well known that coupling atomistic and continuum domains introduces inconsistencies near the interface. These inconsistencies manifest as nonphysical forces, known as “ghost forces,” which can lead to significant errors in the solution. In this paper, we propose a novel approach to achieve a consistent atomistic-continuum interface for the quasicontinuum method, applicable to two-body potentials with unlimited range of interaction. To this end, artificial nodes and elements are introduced located at specified positions, and appropriate constraints are applied. We show that in this way, not only ghost forces are eliminated but also the energy remains compatible through the interface. The method is applied to model surface effect and void defect in static problems, as well as to simulate wave propagation. The results demonstrate that the approach substantially improves accuracy in both static and dynamic problems.</div></div>","PeriodicalId":93433,"journal":{"name":"Forces in mechanics","volume":"19 ","pages":"Article 100311"},"PeriodicalIF":3.2,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143716068","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}
Pub Date : 2025-02-21DOI: 10.1016/j.finmec.2025.100310
Reza Barkhordari , Mehdi Ganjiani , Shahram Etemadi Haghighi
This research investigates the evolution of plastic strain-induced damage and martensite transformation at ambient temperature in austenitic stainless steels AISI-316. A constitutive model is developed within the Continuum Damage Mechanics framework to account for strain-induced phase transformation and damage growth during plastic deformation. This model is implemented using the UMAT subroutine in ABAQUS/STANDARD for numerical simulations. Experimental tests, including tensile and torsional tests with loading-unloading, have been conducted to assess the damage. X-ray diffraction has been used to measure the volume fraction of martensite. This 3D model accurately predicts the hardening behavior, martensite evolution, and damage growth at room temperature. Simulation results and experimental data have been compared for verification purposes.
{"title":"Investigating the orthotropic damage and phase trans-formation for steel 316 at ambient temperature","authors":"Reza Barkhordari , Mehdi Ganjiani , Shahram Etemadi Haghighi","doi":"10.1016/j.finmec.2025.100310","DOIUrl":"10.1016/j.finmec.2025.100310","url":null,"abstract":"<div><div>This research investigates the evolution of plastic strain-induced damage and martensite transformation at ambient temperature in austenitic stainless steels AISI-316. A constitutive model is developed within the Continuum Damage Mechanics framework to account for strain-induced phase transformation and damage growth during plastic deformation. This model is implemented using the UMAT subroutine in ABAQUS/STANDARD for numerical simulations. Experimental tests, including tensile and torsional tests with loading-unloading, have been conducted to assess the damage. X-ray diffraction has been used to measure the volume fraction of martensite. This 3D model accurately predicts the hardening behavior, martensite evolution, and damage growth at room temperature. Simulation results and experimental data have been compared for verification purposes.</div></div>","PeriodicalId":93433,"journal":{"name":"Forces in mechanics","volume":"19 ","pages":"Article 100310"},"PeriodicalIF":3.2,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143521140","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}
Pub Date : 2025-02-15DOI: 10.1016/j.finmec.2025.100307
B. Omolofe, N.P. Okafor
In this study, dynamic characteristics of a simply supported double-beam system under the actions of harmonic variable magnitude travelling load was investigated. The system is made up of two parallel prismatic thick beams connected constantly by a layer of viscoelastic material. The governing equations describing the motion of this double-beam when under the actions of a moving load is a set of two fourth order non homogeneous partial differential equations with singular and variable coefficients. To solve this coupled partial differential equations, a versatile method of solution capable of treating this class of problem for all variants of boundary conditions is employed. This involves the application of the Generalized Fourier Sine Transform Method (GFSTM), in conjunction with a modified Asymptotic Method of Struble (AMS) and the Differential Transform Method (DTM). The GFSTM was employed in the first instance to transform the set of partial differential equations of order four governing the motions of the structural members into a sequence of coupled second order ordinary differential equations. The transformed coupled ordinary differential equations was further simplified using AMS. The differential transform method was finally applied to obtain a mathematical expressions representing the coordinates in modal space. Thus, an approximate analytical solutions representing the displacement amplitude of the double-beam system under the action of the traversing load was obtained for the moving force and moving mass models respectively. Analysis of the approximate analytical solutions was presented. Various results were discussed and displayed in plotted curves. Effects of some vital load and structural parameters on the response characteristics of the beam-load system were examined and presented. Conditions under which the systems experiences resonance phenomenon were established and reported.
{"title":"Response characteristics analysis of a simply supported double-beam system under harmonic variable magnitude travelling load","authors":"B. Omolofe, N.P. Okafor","doi":"10.1016/j.finmec.2025.100307","DOIUrl":"10.1016/j.finmec.2025.100307","url":null,"abstract":"<div><div>In this study, dynamic characteristics of a simply supported double-beam system under the actions of harmonic variable magnitude travelling load was investigated. The system is made up of two parallel prismatic thick beams connected constantly by a layer of viscoelastic material. The governing equations describing the motion of this double-beam when under the actions of a moving load is a set of two fourth order non homogeneous partial differential equations with singular and variable coefficients. To solve this coupled partial differential equations, a versatile method of solution capable of treating this class of problem for all variants of boundary conditions is employed. This involves the application of the Generalized Fourier Sine Transform Method (GFSTM), in conjunction with a modified Asymptotic Method of Struble (AMS) and the Differential Transform Method (DTM). The GFSTM was employed in the first instance to transform the set of partial differential equations of order four governing the motions of the structural members into a sequence of coupled second order ordinary differential equations. The transformed coupled ordinary differential equations was further simplified using AMS. The differential transform method was finally applied to obtain a mathematical expressions representing the coordinates in modal space. Thus, an approximate analytical solutions representing the displacement amplitude of the double-beam system under the action of the traversing load was obtained for the moving force and moving mass models respectively. Analysis of the approximate analytical solutions was presented. Various results were discussed and displayed in plotted curves. Effects of some vital load and structural parameters on the response characteristics of the beam-load system were examined and presented. Conditions under which the systems experiences resonance phenomenon were established and reported.</div></div>","PeriodicalId":93433,"journal":{"name":"Forces in mechanics","volume":"19 ","pages":"Article 100307"},"PeriodicalIF":3.2,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143422105","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}
Pub Date : 2025-02-01DOI: 10.1016/j.finmec.2024.100302
Abdul Aabid , Muhammad Nur Syafiq Bin Rosli , Meftah Hrairi , Muneer Baig
In this study, a fiber-reinforced composite patch was bonded to one side of a cracked aluminum plate using Araldite-2014 adhesive. Experimental tensile tests were conducted on both repaired and unrepaired plates, with further analysis of the effects of patch material and dimensions performed using ANSYS simulations. The effectiveness of the patch repair was evaluated through the stress intensity factor (SIF), as obtained from both experimental and finite element methods. To optimize patch parameters—such as material, thickness, width, and height design of experiments (DOE) approach was applied. Results indicate that the use of fiber-reinforced composite patches is an effective technique for repairing cracked aluminum structures, as it significantly reduces SIF. The findings suggest that repair efficiency can be further enhanced by carefully considering key factors such as patch dimensions, adhesive thickness, and crack length.
{"title":"Enhancing repair of cracked plate using fiber-reinforced composite patch: Experimental and simulation analysis","authors":"Abdul Aabid , Muhammad Nur Syafiq Bin Rosli , Meftah Hrairi , Muneer Baig","doi":"10.1016/j.finmec.2024.100302","DOIUrl":"10.1016/j.finmec.2024.100302","url":null,"abstract":"<div><div>In this study, a fiber-reinforced composite patch was bonded to one side of a cracked aluminum plate using Araldite-2014 adhesive. Experimental tensile tests were conducted on both repaired and unrepaired plates, with further analysis of the effects of patch material and dimensions performed using ANSYS simulations. The effectiveness of the patch repair was evaluated through the stress intensity factor (SIF), as obtained from both experimental and finite element methods. To optimize patch parameters—such as material, thickness, width, and height design of experiments (DOE) approach was applied. Results indicate that the use of fiber-reinforced composite patches is an effective technique for repairing cracked aluminum structures, as it significantly reduces SIF. The findings suggest that repair efficiency can be further enhanced by carefully considering key factors such as patch dimensions, adhesive thickness, and crack length.</div></div>","PeriodicalId":93433,"journal":{"name":"Forces in mechanics","volume":"18 ","pages":"Article 100302"},"PeriodicalIF":3.2,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143129661","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}
Pub Date : 2025-02-01DOI: 10.1016/j.finmec.2024.100303
Amir Mousavi , M.R.M. Aliha , Hadi Khoramishad , Hamid Reza Karimi
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 KIc values (1.22 to 1.54 MPa√m). Especially if the KIc was measured by compressive specimens (ENDC and DNDC with KIc of 1.22 and 1.30 MPa√m, respectively) and was neglected. In these cases, the difference in measured KIc values directly relates to the T-stress value in pure mode-I. So, higher T-stress values increase the KIc and vice versa. In pure mode-III, which can only simulated by ENDB, ENDC, and DNDC specimens, the difference in measured KIIIc 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 KIIIc for specimens shows the same as KIc, KIIIc also has a direct relation with the T-stress. The affectability of fracture toughness from T-stress shows the importance of accounting for it in calculations. The trends show that the ENDB, ENDC, and DNDC specimens have considerably negative T-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 T-stress is almost constant moderate-negative in all the mixed mode I/III conditions (about -2.1 MPa).
{"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}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号