Model For Static Analysis Research Articles

Contact analysis and simulation of high performance round link chain

High performance round link chains are applied in many fields, such as mining, metallurgy, hoisting, shipping, etc. and accidents can easily happen under the condition of bad or complicated working conditions. This paper studies the dynamic analysis of the round link chain transmission process. The kinematics analysis is carried out first, and then the dynamic analysis is carried out after the force analysis of each component. By establishing the mathematical equation of the structural model of the round chains chain, the two static analysis models for the contact of the chain link are derived. Then, the collision process between the round link chains is simulated and analysed. Finally, fatigue fracture mechanism of round link chain and the propagation law of fatigue crack are studied, also, experiments verified that the round link chain satisfies the actual requirement in special needs such as mining.

Static model analysis and identification for serial articulated manipulators

Abstract Many applications of industrial manipulators, such as robot tracking tasks and lead-through programming, require the availability of a static model, which can compensate the gravity and joint friction accurately. Compared with dynamic model, static model identification is more attainable in practice, as it only requires measurement of joint position instead of joint velocity and acceleration. However, there is still no systematical approach for static model identification for general serial articulated manipulators. In this paper, we propose a static model for serial articulated manipulators based on the analysis with standard Denavit–Hartenberg (DH) convention. Then, a theorem is given to obtain a non-singular regression matrix for static model identification, where the ordinary least squares can be applied directly. With well conditioned regression matrix, a static model identification procedure is proposed. Both simulation and experimental results on a 6 DoF manipulator show that the proposed procedure is powerful and practical. Finally, an application of the identified static model in lead-through programming is presented for the validation of the proposed methods.

Assumption of Constraining Force to Explain Distortion in Laser Additive Manufacturing.

Distortion is a common but unrevealed problem in metal additive manufacturing, due to the rapid melting in metallurgy and the intricate thermal-mechanical processes involved. We explain the distortion mechanism and major influencing factors by assumption of constraining force, which is assumed between the added layer and substrate. The constraining force was set to act on the substrate in a static structural finite element analysis (FEA) model. The results were compared with those of a thermal-mechanical FEA model and experiments. The constraining force and the associated static structural FEA showed trends in distortion and stress distribution similar to those shown by thermal-mechanical FEA and experiments. It can be concluded that the constraining force acting on the substrate is a major contributory factor towards the distortion mechanism. The constraining force seems to be primarily related to the material properties, temperature, and cross-sectional area of the added layer.

A sinus shear deformation model for static analysis of composite steel-concrete beams and twin-girder decks including shear lag and interfacial slip effects

A beam model is developed for the static analysis of composite steel-concrete beams and twin-girder decks which takes into account the effects of shear lag phenomenon as well as the interfacial slip between the concrete slab and steel joists. A sinus distribution is considered for the axial displacements of the concrete slab and steel joists. This kinematic represents the transverse shear strain in the concrete slab and steel joists using a cosine function. The considered kinematic satisfies the boundary conditions of transverse shear stress on the top and bottom surfaces and does not need any shear correction factor. The shear lag effects are introduced by prescribing the warping shape of the slab cross-section and taking its intensity as axial unknowns. A conforming three-nodded 25-dof beam element is derived for numerical simulations. The presented model has been validated by comparing the obtained results with elasticity solutions, 3D finite element results and other analytical and numerical models available in the open literature.

A 3D model for static and dynamic analysis of an offshore knuckle boom crane

The paper presents a spatial model of a crane consisting of two booms connected by means of a knuckle. Change of the crane radius and position of booms is realised by length change of cylinders. The crane model takes into account flexibility of booms, cylinders and the rope system. The rigid finite element method is used for discretisation of booms. The computer programme developed on the basis of the model presented enables calculations of dynamic and static analysis to be carried out. The software package is used by designers from PROTEA to test the crane during handling operations in conditions at sea. The model has been validated for tasks of lifting the load with a given velocity both from the air and base. Results of numerical simulations are compared with those of experimental measurements on the test stand.

Assessment of Vibrational Frequencies and Static Characteristics of Multilayered Skew Magneto-Electro-Elastic Plates: A Finite Element Study

This article presents a finite element (FE) model for free vibration and static analysis of layered skew magneto-electro-elastic (SMEE) plates by incorporating the shear deformation theory. The coupled constitutive equations of the MEE materials are used to derive the FE model accounting the effect of electro-elastic and magneto-elastic couplings. The displacement, electric potential and magnetic potential are considered as primary variables, while the stresses, electric displacement and magnetic induction are derived from the primary variables using constitutive equations. Influence of boundary conditions and material stacking sequences on the natural frequency, displacement and stresses of the SMEE plates has been investigated. Particular emphasis has been put on studying the effect of skew angles and aspect ratios on the natural frequencies, stresses, electric displacement and magnetic induction. The present study reveals that skew angle and aspect ratio significantly influence the structural behavior of SMEE plates.

A refined layerwise finite element modeling of delaminated composite laminates with piezoelectric layers

A finite element model for static response and free vibration analysis of delaminated composite laminates with active layers is developed based on a coupled layerwise laminate theory. The proposed model assumes full layerwise variations for both mechanical displacements and the electric field, and more importantly, both strong and weak discontinuous functions are introduced into the displacement fields to model the displacement discontinuity induced by the delamination and strain discontinuity induced by the interface between the layers, respectively. This refined layerwise mechanics can give a more accurate description of displacement discontinuity. The formulation naturally includes the coupling and interactions between the composite laminates and piezoelectric layers. Various examples are investigated by the developed model and the results are compared with previously obtained alternative solutions or experimental results to verify the justification and accuracy of the present formulation. Finally, the effect of delamination on static response and vibration mode are studied in detail to provide beneficial information for the promising damage identification techniques.

Five-degrees-of-freedom model for static analysis of linear roller bearing subjected to external loading

This paper presents a novel five degrees-of-freedom model for the static analysis of linear roller bearings subjected to external loading. In this study, first, a rigid analytical model was developed to obtain the roller contact loads and displacements of carriage caused by the elastic deformation at the roller–carriage and roller–rail contacts. The non-Hertzian contact loads between the rollers and raceways were utilized to consider the profiled roller and/or profiled guide rail. Next, the structural deformations of the carriage owing to the contact loads were computed using the finite element method. The associated displacements of the carriage top were derived systematically. Then, the total displacements of the carriage top were obtained by summing the displacements estimated from the rigid model and the induced structural displacements obtained by finite element method. The proposed model was validated by comparing the calculated displacements of the carriage with those from a commercial program under various loading conditions. Further investigation regarding the effect of preload on displacements of the linear roller bearing was conducted. The simulation results showed the dependence of carriage rigidity and internal load distribution on the linear roller bearing characteristics.

Continuum Model for Static and Dynamic Analysis of Suspension Bridges with a Floating Girder

Continuum Model for Static and Dynamic Analysis of Suspension Bridges with a Floating Girder

Analisis Permintaan Beras di Provinsi Kalimantan Tengah

The purpose of this study is to analyzes the factors that influence the function of demand for rice in the province of Central Kalimantan during the last 20 years, and to determine the elasticity of demand for rice in the province of Central Kalimantan.
 Purposively making research sites in The Province of Central Kalimantan. Data collected in the form of secondary data that is demand for rice in the province of Central Kalimantan during the last 20 years with methods of literature arid study the documents that have been provided are obtained from agencies 1-nd private or government institutions that are related to this research The data analysis using Cobb Douglas function.
 The result of this study is that static analysis model adjusted R2 value of 0.945, which means the proportion of the contribution of independent variables to dependent variable amounted to 94.50%, while the remaining 5.50% is explained by other variables outside the- research such as taste, flavor and consumer Preference. Based on F test variable price of rice, the price of instant noodles, per capita income, population, and education together significantly affected the demand for rice. Based on t-test variable number of people significantly influence demand of rice at the rate of 95%, while per capita income and education variables significantly influence demand for rice at 90% confidence level. The variables specified in the model and does not affect the demand for rice in the Province of Central Kalimantan is the price of rice and the prices of instant noodles. Elasticity of demand for static model based on price elasticity, price inelastic. Based on cross elasticity, the price of instant noodles do not include substitute goods. Based on the income elasticity, per capita income, is inferior.

The structural optimization of roadheader conical picks based on fatigue life

Conical picks are the key cutting components used on roadheaders, and they are replaced frequently because of the bad working conditions. Picks did not meet the fatigue life when they were damaged by abrasion, so the pick fatigue life and strength are excessive. In the paper, in order to reduce the abrasion and save the materials, structure optimization was carried out. For static analysis and fatigue life prediction, the simulation program was proposed based on mathematical models to obtain the cutting resistance. Furthermore, the finite element models for static analysis and fatigue life analysis were proposed. The results indicated that fatigue life damage and strength failure of the cutting pick would never happen. Subsequently, the initial optimization model and the finite element model of picks were developed. According to the optimized results, a new type of pick was developed based on the working and installing conditions of the traditional pick. Finally, the previous analysis methods used for traditional methods were carried out again for the new type picks. The results show that new type of pick can satisfy the strength and fatigue life requirements.

Fracture Analyses of Cracked Delta Eye Plates in Ship Towing

Based on fracture mechanics, a safety analysis approach is proposed for cracked delta eye plates in ship towing. The static analysis model is presented when the delta eye plate is in service, and the fracture criterion is introduced on basis of stress intensity factor, which is estimated with domain integral method. Subsequently, three-dimensional finite element analyses are carried out to obtain the effective stress intensity factors, and a case is studied to demonstrate the reasonability of the approach. The results show that the classical strength theory is not applicable to evaluate the cracked plate while fracture mechanics can solve the problem very well, and the load level, which a delta eye plate can carry on, decreases evidently when it is damaged.

A sound abstract memory model for static analysis of C programs

Abstract memory model plays an important role in the static analysis of programs. This paper proposes a region-based symbolic three-valued logic (RSTVL) to guarantee the soundness of static analysis, which utilises abstract regions to simulate blocks of the concrete memory. RSTVL applies symbolic expressions to express the value of memory objects, and the interval domain to describe the value of each symbol of symbolic expressions. Various operations for memory objects can be mapped to operations about regions. As a sound abstract memory model, RSTVL can describe the shape information of data structure in memory and the storage state of memory objects for C programs, and a variety of associative addressable expressions, including the point-to relations, hierarchical and valued logic relations. We have built a prototype tool DTSC_RSTVL that detects code level defects in C programs. Five popular C programs are analysed, the results indicate that the analysis is sufficiently sound to detect code level defects with zero false negative rate.

A sound abstract memory model for static analysis of C programs

A sound abstract memory model for static analysis of C programs

Dynamic analysis of composite propeller of ship using FEA

Ships and underwater vehicles use propeller for propulsion. In general, propellers are used as propulsors and they are also used to develop significant thrust to propel the vehicle at its operational speed and RPM. The blade geometry and design are more complex involving many controlling parameters. In current years the increased need for light weight structural element with composite materials has led to use of S2 glass fabric/epoxy to propeller. The present research work is to carry out the model and static analysis of aluminium, composite material which is a combination of glass fibre reinforced plastics (GFRP) materials. The research work deals with modelling and analysing the propeller blade of an underwater vehicle for their strength. A propeller is a complex geometry which requires high end modelling software. The solid model of propeller is developed in CATIA V5 R21. Static model analysis of the propellers made of aluminium and composite materials are carried out in advanced numerical simulation systems (ANSYS). We applied thrust force at blade blend section and centrifugal force at the centre of gravity and found out Von Mises stresses, total deformation, directional deformation, principal and shear stresses of aluminium and composite propeller.

Static analysis and process model transformation for an advanced business process to Petri net mapping

SummaryVerification of business processes typically relies on Petri net–based process models. While they allow for natural modeling and analysis of aspects such as parallelism and message exchange, such a process model is seldom complete and precise. This is mainly because the available techniques for deriving a Petri net model from the original model neglect process data in favor of feasible verification. In this paper, we present an approach for deriving more precise process models by leveraging a process‐to‐Petri‐net compiler, which takes as input a business process and generates as output a Petri net model for the process. This can be subsequently used for verification. However, in contrast to a conventional compiler, our compiler's objective is not to create the most efficient code but rather to produce a most precise but still effectively verifiable Petri net–based process model.

Static and Dynamic Performance Simulation of Direct-Acting Force Motor Valve

This work focuses on static and dynamic characteristics of direct-acting force motor valve. First, we analyzed the structure features and operating principle of the Mitsubishi-Hitachi force motor valve (FMV) and the operating principle of its internal permanent-magnet moving-coil force motor magnetic circuit, determined the transfer function of the FMV force motor system, and established a mathematical model for the system. Secondly, we established a static performance analysis model using the AMESIM software and utilized the model in combination with experimental results to analyze the effects of electro-hydraulic servo valve structural parameters on static characteristics. Lastly, we deduced the trajectory equation of the system, established the relationship between dynamic characteristic indexes and structural parameters, and analyzed the effects of different parameter values on the dynamic characteristics of the system. This research can provide a theoretical guidance for designing and manufacturing the FMV body.

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.