cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.14325188.v1
title: Evaluation of 12 m Long Turned Down Guardrail End Terminal Using Full-Scale Crash Testing and Simulation

description: Abstract The beginnings and ends of guardrail designs have the function of providing adequate anchorage for the rest of the system. They should also demonstrate crashworthy performance and should not pose any hazard for errant vehicles. In Europe, the ends of guardrail systems traditionally have incorporated turned down end terminals. Due to its low cost, Turkey also adopted turned down guardrail end terminal, and the majority of these designs are 12 meters long. Accident statistics clearly demonstrate that this particular end terminal poses safety risks for impacting vehicles. However, crash tests performed on the system showed that it worked satisfactorily for cars impacting at 80 kph. In this study, a detailed finite element analysis was performed on a 12 m long turned down guardrail end treatment to fully evaluate its crashworthiness. Data obtained from previously performed TT 2.1.80 and TT 4.2.80 crash tests were used to verify the fidelity of finite element models used in the study. Further simulations performed in accordance with EN1317 part 7 at 100 kph demonstrated unacceptable performance for the end terminal. Results of the study are summarized and recommendations are presented.
DOI: 10.6084/m9.figshare.14325188
title: Evaluation of 12 m Long Turned Down Guardrail End Terminal Using Full-Scale Crash Testing and Simulation

description: Abstract The beginnings and ends of guardrail designs have the function of providing adequate anchorage for the rest of the system. They should also demonstrate crashworthy performance and should not pose any hazard for errant vehicles. In Europe, the ends of guardrail systems traditionally have incorporated turned down end terminals. Due to its low cost, Turkey also adopted turned down guardrail end terminal, and the majority of these designs are 12 meters long. Accident statistics clearly demonstrate that this particular end terminal poses safety risks for impacting vehicles. However, crash tests performed on the system showed that it worked satisfactorily for cars impacting at 80 kph. In this study, a detailed finite element analysis was performed on a 12 m long turned down guardrail end treatment to fully evaluate its crashworthiness. Data obtained from previously performed TT 2.1.80 and TT 4.2.80 crash tests were used to verify the fidelity of finite element models used in the study. Further simulations performed in accordance with EN1317 part 7 at 100 kph demonstrated unacceptable performance for the end terminal. Results of the study are summarized and recommendations are presented.
DOI: 10.6084/m9.figshare.14325189
title: On Micro-Buckling of Unidirectional Fiber-Reinforced Composites by Means of Computational Micromechanics

description: Abstract Micro-buckling of unidirectional fiber-reinforced composites is investigated in this paper by means of an explicit representation of a geometrically imperfect fiber within the context of kinematical and material non-linear behavior. Two types of fiber imperfections are considered: a helicoidal shape, identified as 3D imperfection; and a sinusoidal plane shape (2D imperfection). Both imperfection models are characterized by a maximum misalignment angle of the fiber with respect to the ideal or perfect configuration, as is usually considered in this field. A total of 816 cases were computed in terms of imperfection type (either 2D or 3D), fiber volume fraction, fiber arrangement (square or hexagonal array), orientation for 2D models, matrix yield stress, and misalignment angle. Two load cases, with constrained and unconstrained transverse strain, were considered. Assuming periodic boundary conditions, homogenization was carried out to obtain macroscopic stresses. Numerical results are compared with an analytical model available in the literature. The results show a high imperfection-sensitivity for small misalignment angles; on the other hand, the type of imperfection and the fiber arrangement do not have a large influence on the results. In addition, it was found that this problem is governed by fiber volume fraction and matrix yield stress only for small imperfections, whereas for large misalignment angles, a change in fiber volume fraction produces small changes in micro-buckling stress.
DOI: 10.6084/m9.figshare.14325191.v1
title: Prediction of Modal Damping of FRP-Honeycomb Sandwich Panels with Arbitrary Geometries

description: Abstract In this work, the modal characteristics, including modal damping, of FRP composite skin, honeycomb core sandwich panels with arbitrary geometries are computed using a mixed finite element-meshless method. By using the meshless node distribution scheme in conjunction with the lagrangian quadrilateral interpolating functions, the continuity of inter-elemental displacements is assured. Since the distribution of the elements is not limited to the geometry of the problem, any arbitrary geometry can be readily analysed by using the same node and element distributions. Using the first order shear deformation plate theory, together with a structural damping model, modal response results are produced for a number of sandwich panel geometries, including triangular, trapezoidal, circular as well as rectangular plates with different combinations of free and clamped edges. Results are compared with those reported in the literature, showing the viability and the accuracy of the method.
DOI: 10.6084/m9.figshare.14325191
title: Prediction of Modal Damping of FRP-Honeycomb Sandwich Panels with Arbitrary Geometries

description: Abstract In this work, the modal characteristics, including modal damping, of FRP composite skin, honeycomb core sandwich panels with arbitrary geometries are computed using a mixed finite element-meshless method. By using the meshless node distribution scheme in conjunction with the lagrangian quadrilateral interpolating functions, the continuity of inter-elemental displacements is assured. Since the distribution of the elements is not limited to the geometry of the problem, any arbitrary geometry can be readily analysed by using the same node and element distributions. Using the first order shear deformation plate theory, together with a structural damping model, modal response results are produced for a number of sandwich panel geometries, including triangular, trapezoidal, circular as well as rectangular plates with different combinations of free and clamped edges. Results are compared with those reported in the literature, showing the viability and the accuracy of the method.
DOI: 10.6084/m9.figshare.14325192
title: Finite Element Study of Three Different Treatment Designs of a Mandibular Three Implant-Retained Overdenture

description: Abstract This study compares ball, bar-clip and bar-ball attachment systems for implant-retained mandibular overdentures with three implants. The first implant is placed in the middle of the mandible and the other two are imbedded in the first premolar regions. Linear elastic finite element analysis is used for design analysis. Three dimensional geometry of the mandible is generated from computed tomography. Other parts are modeled using SolidWorks software. The foodstuff is positioned at the right first molar, representing the most frequent masticating situation. To obtain accurate mesh-independent results, finite element models are solved using several mesh grids. They are then validated by means of a detailed convergence analysis. The results demonstrate that the highest von-Mises stress in the bone is always located around the neck of the implant, at its upper threads. Ball and bar-ball attachments transfer the highest and lowest stresses to the bone surrounding the implants, respectively. The lowest stresses in the cortical and cancellous bones are due to bar-ball attachment. Yet, the overdenture gets its maximum movement for this arrangement. Consequently, the use of bar-ball attachment is only recommended for the cases in which stress transferred to peri-implant bone is more important than overdenture stability. Among the three treatment designs, ball attachment seems to exhibit the lowest lateral and overall displacements and hence, better overdenture stability.
DOI: 10.6084/m9.figshare.14325195.v1
title: Effect of Humidity on The Fatigue Behaviour of Adhesively Bonded Aluminium Joints

description: Abstract The present work focuses on the effects of water degradation on the fatigue behaviour of adhesive joints bonded with aluminium adherends. The objective of this study is to measure the influence that humidity has on the fatigue crack growth velocity of two distinct adhesives characterized using the Paris Law, using double cantilever beam (DCB) specimens in unaged and various aged conditions loaded in mode I in order to understand the influence that water content has on the Paris Law constants. It was found that the slope of the Paris Law curve is not heavily changed with the presence of water, but a shift in the curves does occur, generally resulting in a crack initiating at a lower threshold than in the unaged adhesive. Based on this behaviour, it can be concluded that an increase in water content reduces the fatigue joint strength and lifespan of adhesive joints bonded with the studied adhesives.
DOI: 10.6084/m9.figshare.14325195
title: Effect of Humidity on The Fatigue Behaviour of Adhesively Bonded Aluminium Joints

description: Abstract The present work focuses on the effects of water degradation on the fatigue behaviour of adhesive joints bonded with aluminium adherends. The objective of this study is to measure the influence that humidity has on the fatigue crack growth velocity of two distinct adhesives characterized using the Paris Law, using double cantilever beam (DCB) specimens in unaged and various aged conditions loaded in mode I in order to understand the influence that water content has on the Paris Law constants. It was found that the slope of the Paris Law curve is not heavily changed with the presence of water, but a shift in the curves does occur, generally resulting in a crack initiating at a lower threshold than in the unaged adhesive. Based on this behaviour, it can be concluded that an increase in water content reduces the fatigue joint strength and lifespan of adhesive joints bonded with the studied adhesives.
DOI: 10.6084/m9.figshare.14325197
title: Seismic Design and Performance of Dual Moment and Eccentrically Braced Frame System Using PBPD Method

description: Abstract Most structural design codes use elastic analysis to calculate and distribute seismic base shear over the height. This may lead to unsuitable design and may cause undesirable damages to the structure. To solve this problem, in recent years the Performance-based Plastic Design (PBPD) method which considers the plastic behavior of the structure, has been proposed. In this study, the PBPD method is extended to the dual system of moment and eccentrically braced frames. As a code requirement, in dual systems the moment frame must be able to resist at least 25 percent of the base shear. In the proposed PBPD method, the shear resistance of each system is selected at the beginning of design process and this criterion can be contributed to the design process directly. In this regard, three 6, 12 and 20 story structures are designed based on PBPD and conventional method. To assess the behavior of each system, nonlinear pushover and time history analysis are conducted. Results show that dual frames that are designed by PBPD method have less stiffness and strength than frames that are designed by ordinary method. However the yield mechanism is controllable and plastic deformation capacity of structures are better conducted to design in PBPD method. The results also show that the collapse probability of frames that are designed by PBPD method is acceptable.
DOI: 10.6084/m9.figshare.14325197.v1
title: Seismic Design and Performance of Dual Moment and Eccentrically Braced Frame System Using PBPD Method

description: Abstract Most structural design codes use elastic analysis to calculate and distribute seismic base shear over the height. This may lead to unsuitable design and may cause undesirable damages to the structure. To solve this problem, in recent years the Performance-based Plastic Design (PBPD) method which considers the plastic behavior of the structure, has been proposed. In this study, the PBPD method is extended to the dual system of moment and eccentrically braced frames. As a code requirement, in dual systems the moment frame must be able to resist at least 25 percent of the base shear. In the proposed PBPD method, the shear resistance of each system is selected at the beginning of design process and this criterion can be contributed to the design process directly. In this regard, three 6, 12 and 20 story structures are designed based on PBPD and conventional method. To assess the behavior of each system, nonlinear pushover and time history analysis are conducted. Results show that dual frames that are designed by PBPD method have less stiffness and strength than frames that are designed by ordinary method. However the yield mechanism is controllable and plastic deformation capacity of structures are better conducted to design in PBPD method. The results also show that the collapse probability of frames that are designed by PBPD method is acceptable.
DOI: 10.6084/m9.figshare.14325200.v1
title: Campbell Diagrams of a Spinning Composite Shaft with Curvilinear Fibers

description: Abstract This paper presents the vibratory behavior of a spinning composite shaft with curvilinear fibers on rigid bearings in the case of free vibrations. A p-version of finite element is used to define the model. A theoretical study allows the establishment of the kinetic energy and the strain energy of the shaft, necessary to the result of the equations of motion. In this model the transverse shear deformation, rotary inertia and gyroscopic effects have been incorporated. A hierarchical beam finite element with six degrees of freedom per node is developed and employed to find the natural frequencies of a spinning composite shaft with variable stiffness (curvilinear fibers). A computer code is elaborate for calculating the natural-frequencies for various rotating speeds of the composite shafts with curvilinear fibers. In the absence of publications of vibration analysis of rotating composite shafts with curvilinear fibers, the formulation is verified by comparisons with published data on rotating composite shafts reinforced by straight fibers. The influence of the physical, geometrical parameters, the boundary conditions and the curvilinear fiber paths on the first natural frequencies of the spinning composite shafts is studied by plotting various Campbell diagrams.
DOI: 10.6084/m9.figshare.14325200
title: Campbell Diagrams of a Spinning Composite Shaft with Curvilinear Fibers

description: Abstract This paper presents the vibratory behavior of a spinning composite shaft with curvilinear fibers on rigid bearings in the case of free vibrations. A p-version of finite element is used to define the model. A theoretical study allows the establishment of the kinetic energy and the strain energy of the shaft, necessary to the result of the equations of motion. In this model the transverse shear deformation, rotary inertia and gyroscopic effects have been incorporated. A hierarchical beam finite element with six degrees of freedom per node is developed and employed to find the natural frequencies of a spinning composite shaft with variable stiffness (curvilinear fibers). A computer code is elaborate for calculating the natural-frequencies for various rotating speeds of the composite shafts with curvilinear fibers. In the absence of publications of vibration analysis of rotating composite shafts with curvilinear fibers, the formulation is verified by comparisons with published data on rotating composite shafts reinforced by straight fibers. The influence of the physical, geometrical parameters, the boundary conditions and the curvilinear fiber paths on the first natural frequencies of the spinning composite shafts is studied by plotting various Campbell diagrams.
DOI: 10.6084/m9.figshare.14325201
title: Crashworthiness Analysis of S-Shaped Structures Under Axial Impact Loading

description: Abstract To mitigate shock forces in collision events, thin-walled members are used as energy absorber. In this article, crashworthiness of single-cell and multi-cell S-shaped members with various cross-sections including triangular, square, hexagonal, decagon and circular were investigated under axial dynamic loading using finite element code LS-DYNA. Furthermore, crashworthiness of the S-rails with the same outer tubes and different inner ones was studied as well. The multi-cell members employed in this task were double-walled tubes with several ribs connecting the inner and outer tubes together. Modified multi criteria decision making method known as complex proportional assessment (COPRAS) was used to rank the members using three conflicting crashworthiness criteria namely specific energy absorber (SEA), peak crash force (Fmax) and crash force efficiency (CFE). Moreover, the multi-cell S-shaped members were found to perform better than single-cell ones in terms of crashworthiness. In addition, the multi-cell S-rail with decagonal cross-section was found as the best energy absorber, and also the S-rail having the same inner and outer tube with decagonal cross-section displayed desirable crashworthiness performance. Optimum geometry of this S-rail was eventually obtained from the parametric study.
DOI: 10.6084/m9.figshare.14325206
title: Phenomenology of the Maximum Fragment Mass Dependence Upon Ballistic Impact Parameters

description: Abstract Molecular dynamics simulations of the ballistic Taylor test are used to explore correlation between the largest fragment mass and the impact energy of a projectile as well as a set of selected state variables. Flat-ended, monocrystalline, nanoscale bars collide with a rigid wall with striking velocities ranging from 0.27 km/s to 60 km/s. The investigation emphasis is on two border regions of the emerging nonlinear phenomenological model identified with two transitions: the damage-fragmentation transition and the shattering transition. In between these two nonlinear regions, the maximum fragment mass is largely inversely proportional to the impact energy, and the maximum values of the pressure, temperature, and the square of the effective strain. A reverse-sigmoid phenomenological model is proposed to capture the unifying features of this nonlinear and saturable dependence. A crystallographic orientation dependence of the damage-fragmentation transition parameters is investigated.
DOI: 10.6084/m9.figshare.14325206.v1
title: Phenomenology of the Maximum Fragment Mass Dependence Upon Ballistic Impact Parameters

description: Abstract Molecular dynamics simulations of the ballistic Taylor test are used to explore correlation between the largest fragment mass and the impact energy of a projectile as well as a set of selected state variables. Flat-ended, monocrystalline, nanoscale bars collide with a rigid wall with striking velocities ranging from 0.27 km/s to 60 km/s. The investigation emphasis is on two border regions of the emerging nonlinear phenomenological model identified with two transitions: the damage-fragmentation transition and the shattering transition. In between these two nonlinear regions, the maximum fragment mass is largely inversely proportional to the impact energy, and the maximum values of the pressure, temperature, and the square of the effective strain. A reverse-sigmoid phenomenological model is proposed to capture the unifying features of this nonlinear and saturable dependence. A crystallographic orientation dependence of the damage-fragmentation transition parameters is investigated.
DOI: 10.6084/m9.figshare.14318135
title: Interview script with parents and patients

description: Interview script conducted with people with genital ambiguity or with their parents.
DOI: 10.6084/m9.figshare.14318135.v1
title: Interview script with parents and patients

description: Interview script conducted with people with genital ambiguity or with their parents.
DOI: 10.25345/c5br53
title: MassIVE MSV000087109 - Mass spectrometry data collected for the NIH-NP and Euphorbia samples
title: Mass spectrometry data collected for the NIH-NP and Euphorbia samples. Mass spectrometry data collected for the NIH-NP and Euphorbia samples
DOI: 10.6084/m9.figshare.14325207.v1
title: Stress-Based Finite Element Methods for Dynamics Analysis of Euler-Bernoulli Beams with Various Boundary Conditions

description: Abstract In this research, two stress-based finite element methods including the curvature-based finite element method (CFE) and the curvature-derivative-based finite element method (CDFE) are developed for dynamics analysis of Euler-Bernoulli beams with different boundary conditions. In CFE, the curvature distribution of the Euler-Bernoulli beams is approximated by its nodal curvatures then the displacement distribution is obtained by its integration. In CDFE, the displacement distribution is approximated in terms of nodal curvature derivatives by integration of the curvature derivative distribution. In the introduced methods, compared with displacement-based finite element method (DFE), not only the required number of degrees of freedom is reduced, but also the continuity of stress at nodal points is satisfied. In this paper, the natural frequencies of beams with different type of boundary conditions are obtained using both CFE and CDFE methods. Furthermore, some numerical examples for the static and dynamic response of some beams are solved and compared with those obtained by DFE method.
DOI: 10.6084/m9.figshare.14325207
title: Stress-Based Finite Element Methods for Dynamics Analysis of Euler-Bernoulli Beams with Various Boundary Conditions

description: Abstract In this research, two stress-based finite element methods including the curvature-based finite element method (CFE) and the curvature-derivative-based finite element method (CDFE) are developed for dynamics analysis of Euler-Bernoulli beams with different boundary conditions. In CFE, the curvature distribution of the Euler-Bernoulli beams is approximated by its nodal curvatures then the displacement distribution is obtained by its integration. In CDFE, the displacement distribution is approximated in terms of nodal curvature derivatives by integration of the curvature derivative distribution. In the introduced methods, compared with displacement-based finite element method (DFE), not only the required number of degrees of freedom is reduced, but also the continuity of stress at nodal points is satisfied. In this paper, the natural frequencies of beams with different type of boundary conditions are obtained using both CFE and CDFE methods. Furthermore, some numerical examples for the static and dynamic response of some beams are solved and compared with those obtained by DFE method.
DOI: 10.6084/m9.figshare.14325209
title: The Equivalent Linearization Method with a Weighted Averaging for Analyzing of Nonlinear Vibrating Systems

description: Abstract In this paper, the Equivalent Linearization Method (ELM) with a weighted averaging, which is proposed by Anh (Anh, 2015), is applied to analyze some vibrating systems with nonlinearities. The strongly nonlinear Duffing oscillator with third, fifth, and seventh powers of the amplitude, the other strongly nonlinear oscillators and the cubic Duffing with discontinuity are considered. The results obtained via this method are compared with the ones achieved by the Min-Max Approach (MMA), the Modified Lindstedt - Poincare Method (MLPM), the Parameter - Expansion Method (PEM), the Homotopy Perturbation Method (HPM) and 4th order Runge-Kutta method. The obtained results demonstrate that this method is very convenient for solving nonlinear equations and also can be successfully exerted to a lot of practical engineering and physical problems.