cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.14324511.v1
title: Assessment of Homotopy Perturbation Method for Study the Forced Nonlinear Vibration of Orthotropic Circular Plate on Elastic Foundation

description: Abstract In this paper the nonlinear forced vibration of an orthotropic circular plate resting on Winkler, Pasternak and nonlinear Winkler foundation is investigated. Plates with edges elastically restrained against rotation and inplane displacement are analyzed and the Von-Karman geometric nonlinear equations are employed. In this study it is assumed that the plate can be subjected to any periodic distributed lateral loading with respect to time. The Galerkin method is used to obtain Duffing's equation for the central deflection. The Homotopy Perturbation Method was used to study the effects of various parameters including orthotropic parameter, elastic foundation parameters and initial deflection on frequency ratio. Highly accurate results were obtained by the application of the aforementioned method.
DOI: 10.6084/m9.figshare.14324430.v1
title: Effect of Open Crack on Vibration Behavior of a Fluid-Conveying Pipe Embedded in a Visco-Elastic Medium

description: Abstract In this paper vibration behavior of a fluid-conveying cracked pipe surrounded by a visco-elastic medium has been considered. During this work, the effect of an open crack parameters and flow velocity profile shape inside the pipe on natural frequency and critical flow velocity of the system has been analytically investigated. An explicit function for the local flexibility of the cracked pipe has been offered using principle of the fracture mechanics. Comparison between the results of the present study and the experimental data reported in the literature reveals success and high accuracy of the implemented method. It is demonstrated that the existence of the crack in the pipe, decreases the natural frequency and the critical flow velocity so that the system instability onsets at a lower flow velocity in comparison with the intact pipe. Results indicate that the flow velocity profile shape inside the pipe caused by the viscosity of real fluids, significantly affects the critical flow velocity of both intact and fluid-conveying cracked pipe. For instance, as the flow-profile-modification factor decreases from 1.33 to 1.015, the dimensionless critical flow velocity of intact clamped-clamped pipe increases from 5.45 to 6.24.
DOI: 10.6084/m9.figshare.14324428.v1
title: Bone Anisotropy - Analytical and Finite Element Analysis

description: Abstract A human femur model, submitted to static loads, is analyzed through the utilization of three material constitutive relationships, namely: isotropic, transversally isotropic and orthotropic. The influence of bone anisotropy with respect to principal stress/strain distribution on human femur external surface was accessed through the use of analytical and finite element approaches. The models results show that the principal angles at a medial path bone surface have a good correlation with human femur bone lamellae angles.
DOI: 10.6084/m9.figshare.14324254.v1
title: Determination of the Appropriate Gradient Elasticity Theory for Bending Analysis of Nano-beams by Considering Boundary Conditions Effect

description: Abstract In the present paper, a critique study on some models available in the literature for bending analysis of nano-beams using the gradient elasticity theory is accomplished. In nonlocal elasticity models of nano-beams, the size effect has not been properly considered in governing equations and boundary conditions. It means that in these models, because of replacing of the size effect with the inertia gradient effect, the size dependency has been ignored in bending analysis of nano-beams. Therefore, as the beam dimensions increase in comparison to its material length scale parameter, the obtained solution based on the gradient elasticity theory (either in the nonlocal elasticity theory or the strain gradient elasticity theory) should converge to the classical elasticity solution. Hence, satisfying of boundary conditions is a crucial point. In this paper, governing equations and boundary conditions are presented based on two gradient elasticity theories (i.e., nonlocal elasticity and strain gradient elasticity theories). Also, boundary conditions in strain gradient elasticity theory are modified based on a dimensional analysis approach. The results indicate that the strain gradient elasticity theory captures the size effect more sensitive in comparison with the nonlocal elasticity theory in bending analysis. In addition, modified boundary conditions in strain gradient elasticity theory can lead to converge the classical solution at large scales. To prove that the boundary conditions of nano-beam have the direct effect on mechanical behavior of structure, the size-dependent Young modulus of carbon nanotube (CNT) is investigated and the results show that the prediction of strain gradient elasticity theory with modified boundary conditions is in a good agreement with experimental results.
DOI: 10.6084/m9.figshare.14324214.v1
title: Resistance and elastic stiffness of RHS "T" joints: part I - axial brace loading

description: Abstract This paper presents a study on the behaviour of welded "T" joints between RHS sections under brace axial loading. A finite element model was developed to investigate the influence of some geometrical variables on the joint's response. The brace load (always in tension) was incremented up to joint failure, while the chord was kept unloaded. In the companion paper (part II) a complementary study including chord axial loading is presented. The force-displacement curves corresponding to the different geometries are analyzed and compared, focusing on the failure loads and elastic stiffness. Different failure criteria are discussed and applied to the present curves and a comparison of the numerical results with the Eurocode 3 provisions is presented and discussed.
DOI: 10.6084/m9.figshare.14324181.v1
title: DQ thermal buckling analysis of embedded curved carbon nanotubes based on nonlocal elasticity theory

description: Abstract To investigate the thermal buckling of curved carbon nanotubes (CCNTs) embedded in an elastic medium, nonlocal elasticity theory is employed in combination with the theory of thin curved beams. Differential quadrature (DQ) method is implemented to discretize the resulted governing equations. Solving these equations enables us to estimate the critical temperature and the critical axial buckling load for CCNTs surrounded by an elastic medium and under the effect of a uniform temperature change. The elastic interaction between the nanotube and its surrounding medium is modeled as a Winkler-Pasternak elastic foundation. The fast convergence of the DQ method is demonstrated and also its accuracy is verified by comparing the results with available solutions in the literature. The effects of various parameters such as different boundary conditions, nonlocal parameter, Winkler and Pasternak elastic modulus, temperature and nanotube curvature on the critical buckling temperature and load are successfully studied. The results reveal that the critical buckling load depends significantly on the curvature of the CCNT.
DOI: 10.6084/m9.figshare.14324091.v1
title: Closed-form Solution for Freely Vibrating Functionally Graded Thick Doubly Curved Panel-A New Generic Approach

description: Abstract Today, double curvature shell panels are the main parts of each design because their geometrical characteristics provide high strength to weight ratio, aerodynamic form and beauty for the structures such as boats, submarines, automobiles and buildings. Also, functionally graded materials which present multiple properties such as high mechanical and heat resistant, simultaneously, have attracted designers. So, as the first step of any dynamic analysis, this paper concentrates on presenting a high precision and reliable method for free vibration analysis of functionally graded doubly curved shell panels. To this end, panel is modeled based on third order shear deformation theory and both of the Donnell and Sanders strain-displacement relations. A new set of potential functions and auxiliary variables are proposed to present an exact Levy-type close-form solution for vibrating FG panel. The validity and accuracy of present method are confirmed by comparing results with literature and finite element method. Also, effect of various parameters on natural frequencies are studied which are helpful for designers.
DOI: 10.6084/m9.figshare.14323884.v1
title: Novel Layerwise Shear Correction Factors for Zigzag Theories of Circular Sandwich Plates with Functionally Graded Layers

description: AbstractThe available shear correction factors have mainly been proposed for single-layer rectangular plates with zero shear tractions and isotropic homogenous materials. The present analytical shear factors are especially suitable for the first-order zigzag or layerwise theories of circular sandwich plates with functionally graded cores/face sheets and simultaneous normal and shear tractions. Although the present layerwise correction factors are general, they are evaluated for the modal analyses where effects of the shear correction are more remarkable than those of the stress analyses. It is the first time that the concept of the local shear correction factor is introduced. To present more accurate results, the Mori-Tanaka micromechanical-based material properties model is used instead of the traditional rule of mixtures. The governing equations are solved using the analytical Taylor transform method. Comparisons made among results associated with the known shear correction factors, present results, and results of the three-dimensional theory of elasticity reveal that significant enhancements may occur through using the proposed analytical shear correction factors.
DOI: 10.6084/m9.figshare.14323876.v1
title: Finite element model based on refined plate theories for laminated glass units

description: AbstractLaminated glass units exhibit complex response as a result of different mechanical behavior and properties of glass and polymer foil. We aim to develop a finite element model for elastic laminated glass plates based on the refined plate theory by Mau. For a geometrically nonlinear description of the behavior of units, each layer behaves according to the Reissner-Mindlin kinematics, complemented with membrane effects and the von Kármán assumptions. Nodal Lagrange multipliers enforce the compatibility of independent layers in this approach. We have derived the discretized model by the energy-minimization arguments, assuming that the unknown fields are approximated by bi-linear functions at the element level, and solved the resulting system by the Newton method with consistent linearization. We have demonstrated through verification and validation examples that the proposed formulation is reliable and accurately reproduces the behavior of laminated glass units. This study represents a first step to the development of a comprehensive, mechanics-based model for laminated glass systems that is suitable for implementation in common engineering finite element solvers.
DOI: 10.6084/m9.figshare.14323830.v1
title: An optimal integrated longitudinal and lateral dynamic controller development for vehicle path tracking

description: AbstractIn this paper, an optimal controller for integrated longitudinal and lateral closed loop vehicle/driver dynamics proposed to follow desired path in various driving maneuvers, which also improved maneuverability and stability of vehicle over desired path. Designed controller imposed corrected steering angle and torque on the wheels to keep the vehicle on the desired trajectory whilst modified its handling properties. In the next stage, performance of proposed optimal linear quadratic regulator (LQR) controller compared with Proportional-integrated-derivative (PID) one. The proposed controllers has been implemented on vehicle eight degree of freedom model in MATLAB/Simulink. Then the effects of adaptive controller on vehicle path following has been examined for various maneuvers, by driving on the lane change, J-turn, double lane-change and desired tracks. Finally, longitudinal dynamic performance of vehicle has been investigated during severe braking conditions. Simulation results indicated the dominate efficiency of controller on the vehicle stabilization and path following. Also, it improved longitudinal dynamics performance by preventing wheel lock and reducing stopping distance.
DOI: 10.6084/m9.figshare.14325318.v1
title: Seismic performance evaluation of regular and irregular composite moment resisting frames

description: Abstract In this study, the seismic behavior of regular and irregular composite moment resisting frame (CMRF) buildings was investigated. To this aim, 5, 8, 10, 13 and 15-story CMRFs having concrete filled steel tube columns and composite beams were designed at high ductility level and their performances were evaluated comparatively. The case study CMRF structures were categorized into two groups as regular and irregular in elevation. Examined irregular structures have setbacks in different story levels. During the design and performance analysis, SeismoStruct software was employed. Nonlinear static pushover and incremental dynamic analyses were used in the seismic performance assessment. The uniform and triangular load distributions were considered in the pushover analysis while a total of 22 earthquake acceleration records were utilized in the dynamic analysis. The variation in the lateral response, global yielding value, interstory drift, behavior factor, inherent strength factor, overstrength factor, and ductility factor were examined for the regular and irregular CMRF structures. It was observed that the regular CMRFs were more consistent with the design assumptions as compared to the irregular ones. Moreover, the former exhibited more uniform non-elastic demands over the building height according to the results of the incremental dynamic analysis. Under the seismic scenario adopted, all the building types yielded higher values of the behavior factor complied with the limits available in the code.
DOI: 10.6084/m9.figshare.14325318
title: Seismic performance evaluation of regular and irregular composite moment resisting frames

description: Abstract In this study, the seismic behavior of regular and irregular composite moment resisting frame (CMRF) buildings was investigated. To this aim, 5, 8, 10, 13 and 15-story CMRFs having concrete filled steel tube columns and composite beams were designed at high ductility level and their performances were evaluated comparatively. The case study CMRF structures were categorized into two groups as regular and irregular in elevation. Examined irregular structures have setbacks in different story levels. During the design and performance analysis, SeismoStruct software was employed. Nonlinear static pushover and incremental dynamic analyses were used in the seismic performance assessment. The uniform and triangular load distributions were considered in the pushover analysis while a total of 22 earthquake acceleration records were utilized in the dynamic analysis. The variation in the lateral response, global yielding value, interstory drift, behavior factor, inherent strength factor, overstrength factor, and ductility factor were examined for the regular and irregular CMRF structures. It was observed that the regular CMRFs were more consistent with the design assumptions as compared to the irregular ones. Moreover, the former exhibited more uniform non-elastic demands over the building height according to the results of the incremental dynamic analysis. Under the seismic scenario adopted, all the building types yielded higher values of the behavior factor complied with the limits available in the code.
DOI: 10.6084/m9.figshare.14325321
title: An Analytical Study About the Use of Steel Plate Shear Walls to Improve Lateral Rigidity of Reinforced Concrete Framed Structures

description: Abstract Steel plate shear walls are becoming popular for steel structures. In this study, the use of Steel Plate Shear Walls (SPSW) was discussed to increase the horizontal stiffness of reinforced concrete structures. It was aimed to fix the SPSW elements to the exterior of the building. ABAQUS models of SPSW applied 2D frame samples, which were tested in a previous experimental study, were created. Experimental and analytical horizontal load-top displacement curves were found to be in good agreement. In the study, ABAQUS models of a 6-story and 3D reinforced concrete building were also created. In models, SPSW elements were placed at the exterior of the building. The load capacities of the reinforced and non-reinforced building models were compared. The steel sheet thickness and the number of frame openings at which the SPSW element was placed were considered as the variable parameters.
DOI: 10.6084/m9.figshare.14323717.v1
title: Revisiting Some Developments of Boundary Elements for Thick Plates in Brazil

description: AbstractThis work reviews the developments of Boundary Element Method formulations to solve several types of plate bending problems, including non-linear bending. The formulation is developed and solved using the standard BEM procedure, and different integration approaches were discussed and tested. Object oriented implementation issues are commented. Results were obtained for linear and non-linear elastic bending as well as buckling of selected cases of thick plates, including cases of step variation in thickness under large displacements regime.
DOI: 10.6084/m9.figshare.14323701.v1
title: Transient heat conduction in multiwall carbon nanotubes

description: In this paper, theoretical investigation is performed on two-dimensional transient heat conduction in multiwall carbon nanotubes (MWCNTs) by using a continuum model. Temperature, size and direction dependencies of thermal properties are considered. Both Fourier and non-Fourier heat conduction approaches are used and finite element models are developed to solve the nonlinear equations for MWCNTs. The presented solutions are verified by comparing the results with those reported in the literature. Three types of thick and thin MWCNTs are considered and thermal shock is applied to their cylindrical surfaces or end cross sectional areas. Temperature distributions resulted from both approaches are obtained and compared together. Interesting results are found especially in MWCNTs that are exposed to extreme temperature gradient.
DOI: 10.6084/m9.figshare.14323590.v1
title: Modified Bolle - Reissner Theory of Plates Including Transverse Shear Deformations

description: AbstractIn this work, new equations for first-order shear deformation plates are deduced taking into account the kinematic assumptions of the Bolle-Reissner theory but considering the equilibrium equations in the deformed configuration for the plate. The system of differential equations deduced is applicable to the calculation of the stresses in isotropic plates and is valid for thin and moderately thick plates. Analytical solutions are also presented in this work which are compared, when possible, with the ones obtained with other refined shear deformation plate theories.
DOI: 10.6084/m9.figshare.14323537.v1
title: Inspection of a Rectangular Plate Dynamics Under a Moving Mass With Varying Velocity Utilizing BCOPs

description: AbstractThis research is dedicated to the inspection of a thin rectangular plate dynamic behavior traversed by an accelerated moving mass. BCOPs (boundary characteristic orthogonal polynomials) are utilized to treat the constitutive equation of plate vibration for different boundary conditions. Comprehensive parametric surveys are carried out to shed light on the effects of the plate fixities and aspect ratios as well as the moving mass weight, velocity and acceleration on the plate DAF (dynamic amplification factor). The convenience of adopting the presented solution dealing with various plate fixity cases makes it a superior approach comparing with eigenfunction expansion method.
DOI: 10.6084/m9.figshare.14322376.v1
title: During which period should we avoid cholecystectomy in patients who underwent endoscopic retrograde cholangiopancreatography?

description: ABSTRACT Objective: To determine the period during which we should avoid cholecystectomy after endoscopic retrograde cholangiopancreatography. Methods: A retrospective analysis of electronic medical charts of 532 patients undergoing endoscopic retrograde cholangiopancreatography, between March 2013 and December 2017. Results: Approximately one-third of patients underwent the procedure between 4 and 30 days after endoscopic retrograde cholangiopancreatography. The conversion rate was 3.8%. The need for abdominal drainage and the finding of biliary tract injury after surgery were observed in 15.1% and 1.9% of patients, respectively. The length of stay was significantly shorter among patients undergoing surgery more than 30 days after endoscopic retrograde cholangiopancreatography. These patients had a median length of stay of one day, whereas the median length of stay in the group undergoing the procedure between 4 and 30 days after endoscopic retrograde cholangiopancreatography was 2 days. Conclusion: The period during which we should avoid cholecystectomy is between 4 and 30 days after endoscopic retrograde cholangiopancreatography.
DOI: 10.6084/m9.figshare.14325325
title: Buckling of Axially Compressed Cones with Imperfect Axial Length

description: Abstract The paper considers the effect of imperfect length on the buckling behavior of axially compressed mild steel truncated cone. Three types of initial geometric imperfections with different number of waves along the compressed edge are analyzed, and they are: (i) sinusoidal waves, (ii) triangular waves, and (iii) square waves. A validation of experimental data from previous study and further numerical calculations are provided in this paper. A good repeatability of experimental data was revealed through the test results with only 0% to 7% of error. Numerical simulations were carried out using ABAQUS FE code. It is shown that the buckling load of the cone is differently affected by the shape and amplitude of the imperfection. Apparently, the buckling loads of analyzed cones are less sensitive when imperfection shape is triangular as compared to other imperfection shapes. Furthermore, the effect of number of waves on buckling load of axially compressed cones was investigated for the above three cases. Results indicate that the influence of number of waves on the load carrying capacity of the cone is less significant.
DOI: 10.17870/bathspa.12263129.v1
title: About the Heads - 300-word Statement

description: <i>About the Heads</i> is a response to the collection of stone heads which have been stored in the Undercroft to Queen Anne’s Court at the Old Royal Naval College since the turn of the 18th century. <br>This item contains the 300-word Statement for the project.