Model For Static Analysis Research Articles

Tests on full-scale and static analysis models of the wood-framed building stucture horizontaly loaded

This paper focuses on development of the high energy saving timber building and ecological technology protecting environment in civil engineering. Wood framed with sheathing, large panel structures became more popular building constructions in Poland last decade. Experimental tests and numerical analysis of panels and complete wood framed building have been taken into account. Typical two-story residential building was selected for test. Test of three dimensional (3D) whole building was conducted on the base of experimental investigations results of large panel similar to those used in building structure. Also adequate tests of materials and connections were accompanying of the whole structure investigations. Obtained results were adopted in numerical models elaborated for wall and floor panels and in 3D model of whole building. Load -displacements characteristics were acquired from tests and numerical models. The displacements computed from 3D numerical model were 10–20% higher than from experiment. Experimentally ob-tained lower displacements than those from analytical analysis are resulted from higher stiffness of wall system due to diaphragms interconnections, their common interaction and three-dimensional character of building structure. Presented research analyzed method of computation of internal forces in building as well in the range of engineering methods in the form of rigid beam scheme up to the advanced methods using 3D spatial model adopting FEM.

Discrete and continuous models for static and modal analysis of out of plane loaded masonry

A critical review of analytical and numerical models for studying masonry out of plane behaviour is presented. One leaf historical masonry, composed by rigid blocks arranged regularly with dry or mortar joints, is considered. Discrete model with rigid blocks, Love-Kirchhoff and Reissner-Mindlin plate models and 3D heterogeneous FEM are adopted. An existing simple and effective discrete model is adopted and improved by applying matrix structural analysis techniques for static and modal analysis of masonry walls in the elastic field, but the formulation allows to account also for material nonlinearity. Elastic parameters of both plate models are based on an existing compatible identification between 3D discrete model and 2D plate models. Static and modal analysis of masonry walls with several boundary conditions are carried on, numerical tests account for in plane size of heterogeneity and structure thickness by means of in and out of plane scale factors. Results show that discrete model is simple and effective for representing masonry behaviour, especially when size of heterogeneity is smaller than overall panel size. Decreasing in plane scale factor, plate models converge to the discrete one, but the Reissner-Mindlin one shows a better convergence and also allows adopting a simple FE for performing numerical analysis.

Bayesian switching factor analysis for estimating time-varying functional connectivity in fMRI

There is growing interest in understanding the dynamical properties of functional interactions between distributed brain regions. However, robust estimation of temporal dynamics from functional magnetic resonance imaging (fMRI) data remains challenging due to limitations in extant multivariate methods for modeling time-varying functional interactions between multiple brain areas. Here, we develop a Bayesian generative model for fMRI time-series within the framework of hidden Markov models (HMMs). The model is a dynamic variant of the static factor analysis model (Ghahramani and Beal, 2000). We refer to this model as Bayesian switching factor analysis (BSFA) as it integrates factor analysis into a generative HMM in a unified Bayesian framework. In BSFA, brain dynamic functional networks are represented by latent states which are learnt from the data. Crucially, BSFA is a generative model which estimates the temporal evolution of brain states and transition probabilities between states as a function of time. An attractive feature of BSFA is the automatic determination of the number of latent states via Bayesian model selection arising from penalization of excessively complex models. Key features of BSFA are validated using extensive simulations on carefully designed synthetic data. We further validate BSFA using fingerprint analysis of multisession resting-state fMRI data from the Human Connectome Project (HCP). Our results show that modeling temporal dependencies in the generative model of BSFA results in improved fingerprinting of individual participants. Finally, we apply BSFA to elucidate the dynamic functional organization of the salience, central-executive, and default mode networks—three core neurocognitive systems with central role in cognitive and affective information processing (Menon, 2011). Across two HCP sessions, we demonstrate a high level of dynamic interactions between these networks and determine that the salience network has the highest temporal flexibility among the three networks. Our proposed methods provide a novel and powerful generative model for investigating dynamic brain connectivity.

Design and Simulation of Hybrid Double Solenoid Valve Actuator

This paper proposes a novel hybrid valve actuator (HVA) with permanent magnet (PM) and electromagnet (EM) magnetomotive force (MMF) for variable valve timing camless engine. Traditional double solenoid valve actuator (DSVA) has inherent problem of high power consumption, as armature is at equilibrium position away from electromagnet therefore to move armature to open/close position and for keeping armature latched to EM. Hybrid PM/EM valve actuator is proposed in this study. The finite element analysis is performed with Ansys Maxwell on static characteristics of traditional DSVA and HVA on bases of actuator holding force. The equivalent model of static analysis is introduced into Ansys Simplorer for dynamic analysis. The simulation results depict reduce power consumption and transition time of proposed HDSVA over DSVA.

Conceptual Design of a Small Hybrid Unmanned Aircraft System

UAS (Unmanned Aircraft System) technologies are today extremely required in various fields of interest, from military to civil (search and rescue, environmental surveillance and monitoring, and entertainment). Besides safety and legislative issues, the main obstacle to civilian applications of UAS systems is the short time of flight (endurance), which depends on the equipped power system (battery pack) and the flight mission (low/high speed or altitude). Long flight duration is fundamental, especially with tasks that require hovering capability (e.g., river flow monitoring, earthquakes, devastated areas, city traffic monitoring, and archeological sites inspection). This work presents the conceptual design of a Hybrid Unmanned Aircraft System (HUAS), merging a commercial off-the-shelf quadrotor and a balloon in order to obtain a good compromise between endurance and weight. The mathematical models for weights estimation and balloon static performance analysis are presented, together with experimental results in different testing scenarios and complex environments, which show 50% improvement of the flight duration.

Comparison of Developed Numerical Macro and Micro Masonry Models for Static and Dynamic Analysis of Masonry-infilled Steel Frames

First, the basic characteristics of macro and micro masonry models in numerical analyses of masonry structures are discussed. Afterwards, developed numerical macro and micro masonry models, intended for the nonlinear static and dynamic analysis of unreinforced and confined masonry walls, as well as of masonry-infilled frames, are briefly presented. The models are tested on previously performed experimental tests of masonry-infilled steel frame under horizontal static force and masonry-infilled steel frame on a shake-table. The precision of both models is compared. It is concluded that both numerical models can provide reliable results. However, the macro model has more advantages for wide practical application.

Static and dynamic analyses of insulated concrete sandwich panels using a unified non-linear finite element model

Insulated concrete sandwich panels are comprised of two outer concrete wythes and an inner layer of foam insulation. They have been increasingly used because of their advantages of light weight and energy efficiency. Various shear connectors can be used to connect the two outer concrete wythes. More recently, Fiber-Reinforced Polymer (FRP) shear connectors have been used, which can eliminate thermal bridging and improve the thermal performance. Typical approaches to Finite Element (FE) analysis treat static and dynamic analyses separately. However, due to the flexibility of the FRP shear connectors and the cracking of the concrete in insulated concrete sandwich panels, a nonlinear static analysis model would often diverge early based on a preliminary FE study conducted by the authors. To address this issue, a nonlinear explicit dynamic FE model using ABAQUS© was developed, which can study both the panels’ static behavior under typical flexural loading and dynamic behavior under blast loading. Nonlinear material properties were incorporated and damaged plasticity model was used to model concrete in both compression and tension. In order to simulate the static behavior, the time loading control was applied to the FE model to slow down the rate of loading to smoothly capture the response. For dynamic analysis under blast loading, a verification study was conducted first using the developed FE model, where good correlations can be obtained between the FE and test results on a panel tested in a previous study. The FE model was further used to study the dynamic behavior of two panels under blast loading: one is a solid concrete panel and the other is an insulated concrete sandwich panel. It can be concluded that, although the insulated concrete sandwich panel is lighter, it still performs relatively well compared to the solid panel under blast loading. Therefore, it is promising to use insulated concrete sandwich panels for both conventional and blast-resistant structures.

Nonlinear Finite Element Analysis of Unreinforced Masonry Walls

Most of the monumental structures worldwide and residential structures in developing countries are built in masonry. The studies performed by various researchers prove the vulnerability of masonry structures under various circumstances, especially under earthquakes, so as to necessitate detailed contemplation. In this paper, a numerical model for nonlinear static analysis of unreinforced masonry walls is developed based on a macro-modelling approach. A detailed parametric study is also performed to analyse the effect of wall thickness as well as length on the behaviour of the masonry wall. The present numerical model can be utilized for risk assessment and seismic retrofitting of historical masonry structures.

Straightness error modeling and compensation for gantry type open hydrostatic guideways in grinding machine

This study presents an approach to model and compensate the vertical straightness error of gantry type open hydrostatic guideways. The straightness error is measured at different measurement points on the beam using a laser interferometer. To investigate different trends in the straightness error, a static analysis model is established, based on the error averaging effect considering the guiderail profile error. The linear deviation of the slider is computed and the vertical straightness error is calculated using a least-square method. The simulation results indicate that the measurement points have a big impact on the straightness error. The minimum value appeared when measurement point located at the middle of the X beam. And more closer to Y guide rails, higher value will be. The positions of the measurement points are chosen according to the change trend of the vertical straightness error. Finally, vertical straightness error is compensated and the compensation results are compared between different coordinate values. Experimental results show that the straightness error model and error compensation strategy help to effectively improve the accuracy of gantry type open hydrostatic guideways in grinding machines.

Mesh‐free models for static analysis of smart laminated composite beams

SummaryThis paper is concerned with the development of mesh‐free models for the static analysis of smart laminated composite beams. The overall smart composite beam is composed of a laminated substrate composite beam and a piezoelectric layer attached partially or fully at the top surface of the substrate beam. The piezoelectric layer acts as the distributed actuator layer of the smart beam. A layer‐wise displacement theory and an equivalent single‐layer theory have been used to derive the models. Several cross‐ply substrate beams are considered for presenting the numerical results. The responses of the smart composite beams computed by the present new mesh‐free model based on the layer‐wise displacement theory excellently match with those obtained by the exact solutions. The mesh‐free model based on the equivalent single‐layer theory cannot accurately compute the responses due to transverse actuation by the piezoelectric actuator. The models derived here suggest that the mesh‐free method can be efficiently used for the numerical analysis of smart structures. Copyright © 2016 John Wiley & Sons, Ltd.

Parameter Variations of Identified Model for Static Deformation Analysis of Arch Dam

Parameter Variations of Identified Model for Static Deformation Analysis of Arch Dam

Ai BCS: A GPU cluster scheduling optimization based on SKE model

A GPGPU is very important technology and a research hotspot for cloud computing. We pay close attention to its energy consumption and performance. In this paper, a static performance analysis model of GPU, SKE (Single Kernel Estimate), is set up to analyze the completion time of the kernel function on a GPU to find the optimal parallel solution to different tasks in a specific GPU device and the granularity size of the thread-block division, thus enabling the fastest execution speed of the kernel function. The deviation between the completion time calculated by SKE and the real execution time of the kernel is no more than 13%. On this basis, we calculate the completion time for each sub-GPU task and seek the critical path of the GPU cluster, and propose a GPU cluster scheduling algorithm, BCS (Based on Critical-path-Scheduling). The algorithm regulates the frequency of non-critical nodes, mainly through dynamic voltage and frequency scaling (DVFS) technology, and achieves the goal of reducing the energy consumption of GPU nodes without affecting the final completion time of the cluster. The evaluation results show that BCS reduces energy consumption by a maximum of 9.4%, compared to DRS.

Comparison of numerical models for nonlinear static analysis of planar concrete frames based on 1D and 2D finite elements

Firstly, a discussion about the application of beam‐column (1D) and plane (2D) finite elements in the numerical analysis of the planar concrete frames is presented. Then, briefly are presented two numerical models for nonlinear static analysis of planar concrete frames, first based on beam‐column (1D) elements and second on plane (2D) finite elements, which can simulate their main nonlinear effects. The presented models are verified on two experimental test results. Good agreement was obtained between the experimental and the numerical results, which confirm the possibility of practical application of both presented numerical models. However, their further verifications are necessary.

Finite Element Modelling for Static and Free Vibration Response of Functionally Graded Beam

A 1D Finite Element model for static response and free vibration analysis of functionally graded material (FGM) beam is presented in this work. The FE model is based on efficient zig-zag theory (ZIGT) with two noded beam element having four degrees of freedom at each node. Linear interpolation is used for the axial displacement and cubic hermite interpolation is used for the deflection. Out of a large variety of FGM systems available, Al/SiC and Ni/Al2O3 metal/ceramic FGM system has been chosen. Modified rule of mixture (MROM) is used to calculate the young's modulus and rule of mixture (ROM) is used to calculate density and poisson's ratio of FGM beam at any point. The MATLAB code based on 1D FE zigzag theory for FGM elastic beams is developed. A 2D FE model for the same elastic FGM beam has been developed using ABAQUS software. An 8-node biquadratic plane stress quadrilateral type element is used for modeling in ABAQUS. Three different end conditions namely simply-supported, cantilever and clamped- clamped are considered. The deflection, normal stress and shear stress has been reported for various models used. Eigen Value problem using subspace iteration method is solved to obtain un-damped natural frequencies and the corresponding mode shapes. The results predicted by the 1D FE model have been compared with the 2D FE results and the results present in open literature. This proves the correctness of the model. Finally, mode shapes have also been plotted for various FGM systems.

Numerical model for nonlinear analysis of composite concrete-steel-masonry bridges

This paper firstly briefly describes developed numerical model for both static and dynamic analysis of planar structures made of concrete, steel and masonry. The model can simulate the main nonlinearity of such individual and composite structures. The model is quite simple and based on a small number of material parameters. After that, three real composite concrete-steel-masonry bridges were analyzed using the presented numerical model. It was concluded that the model can be useful in practical analysis of composite bridges. However, future verifications of the presented numerical model are desirable.

Response modification factor due to ductility of screen-grid ICF wall system in high seismic risk zones

Insulating Concrete Form (ICF) includes permanent formworks, most commonly expanded polystyrene foam. Insulating Concrete Forms create a formwork for concrete that stays in place as permanent building insulation. Structures usually experience plastic deformations during major earthquakes; however, because of complexity of performing non-linear analysis, codes consider effects of inelastic behavior through reduction factors (R) and allow linear analysis instead. Reduction factor has not been presented for Screen-Grid ICF (SGICF) wall system until now. In this research, reduction factors due to ductility of SGICF wall systems are determined by non-linear static analysis (Pushover) and Concrete Damaged Plasticity constitutive model (CDP) in ABAQUS 6.12. Then the results are compared to those of the experimental model. Results from this research show that such structural system, if used in high seismic risk zones, has an acceptable ductility.

Reduced Order Models for Static and Dynamic Analysis of Composite Panels Based on a Perturbation Approach

An overview of a specific reduced order modelling technique for Finite Element nonlinear buckling analysis of structures under static and dynamic loading is presented. The reduction method applied makes use of an available, well-established analytical perturbation procedure for static buckling and dynamic buckling analysis. This procedure has in the past years been used as the foundation for the development and implementation of a Finite Element framework for reduced order nonlinear buckling analysis. These achievements are reported, including a concise description of the underlying theory and certain characteristic examples. A basic example of a composite plate and other examples related to aircraft applications demonstrate the capabilities of this reduced order modelling framework for nonlinear buckling and dynamic response analysis and illustrate the current status of its development.

Numerical evaluation of deformation capacity of laced steel-concrete composite beams under monotonic loading

This paper presents the details of Finite Element (FE) analysis carried out to determine the limiting deformation capacity and failure mode of Laced Steel-Concrete Composite (LSCC) beam, which was proposed and experimentally studied by the authors earlier (Anandavalli et al. 2012). The present study attains significance due to the fact that LSCC beam is found to possess very high deformation capacity at which range, the conventional laboratory experiments are not capable to perform. FE model combining solid, shell and link elements is adopted for modeling the beam geometry and compatible nonlinear material models are employed in the analysis. Besides these, an interface model is also included to appropriately account for the interaction between concrete and steel elements. As the study aims to quantify the limiting deformation capacity and failure mode of the beam, a suitable damage model is made use of in the analysis. The FE model and results of nonlinear static analysis are validated by comparing with the load-deformation response available from experiment. After validation, the analysis is continued to establish the limiting deformation capacity of the beam, which is assumed to synchronise with tensile strain in bottom cover plate reaching the corresponding ultimate value. The results so found indicate about 20° support rotation for LSCC beam with 45° lacing. Results of parametric study indicate that the limiting capacity of the LSCC beam is more influenced by the lacing angle and thickness of the cover plate.

An IMA Static Load Balancing Strategy Optimization Method Based on Graph Theory

Aiming at the problem of reconfiguration strategy of integrated avionics system, a method of static load balancing strategy optimization based on graph theory is proposed after satisfying system performance and reliability requirements. This method establishes the IMA static load balancing strategy analysis model based on graph theory and puts forward the load balance evaluation indexes of IMA system:The maximum load value of the system partition obtained by allocating the maximum load value of the processor according to the time slice length;the longest communication link for the transmission of information between tasks;and the maximum traffic volume on the communication line. With the three evaluation indexes synthesizing, the unitary evaluation index of the IMA system load balancing strategy is put forward. On the basis of this method, the future research direction of load balancing of IMA system is prospected.

Selection of effective and highly thermostable Bacillus subtilis lipase A template as an industrial biocatalyst-A modern computational approach

Biocatalysts are intrinsically reactive and hence their operational stability is of vital significance for any bioprocess. The setback in biocatalyst stability has been tackled from diverse prospects. Inherently, stable biocatalysts are markedly realized and a regular attempt is being made to seek out new organisms that harbor them. Here, we analyzed the industrial biocatalyst lipase A (Native) of Bacillus subtilis and its six thermostable mutants (2M, 3M, 4M, 6M, 9M and 12M) computationally using conformational sampling technique. Consequently, the various structural events deciphering thermostability like root mean square deviation, root mean square fluctuation, radius of gyration and polar surface area showed mutant 12M to be highly stable with statistical validation. Besides, static model analysis involving intra-molecular interactions, secondary structure, solvent accessibility, hydrogen bond pattern, simulated thermal denaturation and desolvation energy also supported 12M comparatively. Of note, the presence of high secondary structural rigidity and hydrogen bonds increased thermostability and functionality of 12M, thus selecting it as a best template for designing thermostable lipases in future. Also, this study has a significant implication toward a better understanding of conformational sampling in enzyme catalysis and enzyme engineering.