Papers by Keyword: Static Analysis

Abstract: This article follows earlier publications dealing with reinforced concrete arch overpasses on the D3 0311 motorway section located near Ceske Budejovice, Czech Republic, close to the Austrian border. While previous work provided a basic overview of the bridge’s structural layout and construction, this article focuses on a detailed static analysis and related assessments. Attention is given to serviceability limit states and stability, as well as to the analysis of the construction stages and its possible alternatives. A detailed description of the results from static load testing, including the monitoring of crack initiation and propagation, is presented. The study also addresses the problem of differential shrinkage in the concrete at the arch-deck interface. The results demonstrate that detailed numerical analysis combined with experimental verification through static load testing provides valuable insight for optimizing design and ensuring long-term reliability of these bridge structures.

Abstract: The PTO (Power-take-off) shaft is an essential rotatory component in agricultural tractor, used for transmitting power to shaft-driven implements such as rotary tiller, thresher, PTO driven pump, etc. During field operations, the PTO is subjected to uneven vibrational loads, which often lead to premature failure. These failures pose significant challenges pertinent to structural integrity, product quality as well as customer satisfaction. The current study conducts static and harmonic analysis to observe failure characteristics of conventional medium-carbon steel shaft under torsional loading. This study also explores the utilization of synthetic, natural, and hybrid-based fiber-based polymer composite to optimize overall weight and evaluate the impact of fiber orientation on stress and deformation behavior. The shaft was made up of unidirectional hemp and carbon-bamboo fiber reinforced epoxy, assuming isotropic characteristics for the fibers and polymer. A Representative Volume Element with a hexagonal array of circular fibers was developed using ANSYS Material Designer, maintaining a fiber volume fraction of 0.3 within the matrix. Laminated composites were then modeled using ANSYS Pre-Post Module with varying ply orientation to obtain an optimum configuration. Compared to the results of baseline steel shaft, Carbon fiber, Hemp fiber and Carbon-Bamboo fiber configurations demonstrated a mass reduction of 75.71%, 80% and 77.5%, respectively. These findings highlight the potential of composite PTO shaft as more economical, biodegradable, sustainable and light weight alternatives to steel in modern agricultural applications.

Abstract: There is a growing demand in the dental implant sector which aims to recreate the exact function and appearance of natural teeth, including strength, textures, and seamless blending with nearby teeth. Therefore, choosing the best crown material is a vital and challenging decision. To address this challenge, current study employs a comprehensive approach using Finite Element Analysis (FEA) on a 3-D CAD model. The stress analysis was carried out on three different crown materials - commercially pure Titanium (cp Ti), Zirconia (ZR), and Lithium Disilicate (LD) and compared their performance with that of human tooth material. The computational analysis results reveal that the pure Titanium (cp Ti) crown has shown the least deformation while the LD crown has showed the highest deformation under same loading conditions. When maximum stress is compared, Titanium showed the highest value, followed by Zirconia, whereas Lithium Disilicate (LD) demonstrated stress and deformation levels comparable to those of natural teeth.

Abstract: The paper presents the results of the experimental study of the longitudinal and transverse wall thickness variation at the ends of a oil-well tubing during reduction procedure. It is established that the greatest "contribution" to wall thickness data spread is made by the pipe facets, which is caused by the influence of the reduction regimes and the rolls calibration due to the metal flow into the tapers of groove. In the course of work, recommendations were also made that, in order to reduce the wall thickness variation of pipes, it is necessary to develop the calibration ensuring the decreasing of the intensity of metal flow into the tapers of groove, as well as decrease the reduction at the mill stands, and increase the coefficient of kinematic tension between the stands of the stretch-reducing mill.

Abstract: The most frequent research methods applied in various areas of scientific research are computer modelling and numerical simulation. The trend of using finite element method (FEM) gradually replaces classical methods of exploring phenomena. The method is suitable for investigating technical phenomena in the field of construction, mechanics and strength, as well as in other disciplines. Its suitability for the area of ​​strength will be demonstrated in the current paper which presents solutions to various embeddings of a beam under bend. The beam was loaded with an external uniformly distributed load q(x) along its entire length. The research aim was to determine the maximum load and maximum deflection of the beam depending on the beam position and the material used. The beam under bend was selected as the most commonly used structural element. Analytical solution to bending moment and displacement forces is suitable for simple beam loads. Modelling and numerical simulations provide solution to complex problems and different load variations, while identifying changes in material properties of the structural element under consideration. The results are then evaluated and judged on the basis of the maximum strength of the structural material, while meeting the safety condition of the maximum load or maximum deflection. Modelling via FEM is a flexible research method applicable in all research areas.

Abstract: The main objective of the present study is to give a systematic way for the derivation of laminated composite plates by using the mixed type finite element formulation with a functional. The first order shear deformation plate theory is used. Differential field equations of composite plates are derived from virtual displacement principle. These equations were written in operator form then by using the Gâteaux differential method, a new functional which including the dynamic and geometric boundary conditions is obtained after provide potential conditions. Applying mixed-type finite element based on this new functional, a plate element namely FOPLT32 is derived which have 8 degrees of freedoms on per node, total 32 freedoms. The reliability of the derived FOPLT32 plate elements for static analysis is verified, since the results obtained have been shown to agree well with the existing ones.

Abstract: This paper deals with static and dynamic analysis of asymmetric high-rise building. Two alternatives have been analysed – without dilatation and with dilatation. Then, the influence of the dilatation was discussed. The building was located in 4^th seismic area in Slovakia (Bratislava). The description of the building, applied load, considered soil-structure interaction, created calculating models, used analysis and obtained results are mentioned here. The conclusions and the photos of defective repairs of real structures are depicted at the end of the paper.

Abstract: Modeling and simulation of mechanical structures in development phase are fundamental to optimize and improve the stability and reliability of the final product as well as to reduce the cost of prototyping and testing. Wind turbines are subject to critical loading to the centrifugal force due to wind speed and gravitational force. The present study discusses three-dimensional numerical simulations of combined Darrieus-Savonius wind turbine D-SWT for applications in urban and isolated areas for lighting, pumping water, etc. The Darrieus turbine is used to produce wind power and the Savonius rotor to start the system. Finite Element Analysis (FEA) using SolidWorks 2015 is employed to generate the geometry of the structure and SolidWorks Simulation to investigate the stability and reliability static on the structure of the D-WST built by two types of material of the blade Galvanized Steel (GS) and Aluminum alloys 1060-H18 (ALU). Mechanical parameter of the structure are calculated for critical loading conditions, including the gravity and wind pressure loading due to the wind speed of 23m/s. Simulations results indicate no structural failure is predicted for all components of the D-SWT for both materials used according to Von Mises criterion stresses and the factors of safety of the most fragile material are greater than (the unity) 1. The maximum displacements found (3.84 & 6.81mm), occurred at the tip blades (free ends levels). These displacements are accepted relatively to the structure size.

Abstract: . In this paper a parametric static and torsion analysis on a catamaran ship structure made out of composites materials is performed. The best solution for material selection is based on specific criteria for certain analysis. For dynamic analysis, the main criteria is to obtain the structure natural frequencies in a range, far from the resonance frequencies produced by the ship propulsion installation, wave loads etc. For static analysis the comparative criteria is to obtain the lowest weight of structure for the same strength. Also, buckling item is other criteria for comparative analysis. The comparative analysis is performed between rule based scantling structure and a FEM based structure for a composite material twin hull deck, in order to reduce the total hull weight. Material used for ship deck structure of the analyzed ship is e-glass polyester.

Abstract: Offshore structure, particularly fixed offshore structures, should be kept in the performance for the fit-for-purpose condition during their operating lifetime. For fixed offshore structures that exceed their designated life years, the proper Structural Integrity Management System (SIMS) should be developed and applied. Despite the fixed offshore platforms have their service life, there are still platforms that continue to operate exceeding their service lifetime. These ageing platforms should be taken care thoroughly to avoid the consequences that could take casualties. This paper will propose the proper initiation of SIMS development for ageing fixed offshore platforms in Indonesia, by taking an example at Bekapai Field Platforms in East Kalimantan. Using HAZID technique and several ranking criteria, the platforms are assessed and ranked. Platforms that categorized in critical condition are grouped based on similarities in geometry and function. The highest rank is analyzed in computer Finite Element Analysis (FEA) Software with modification based on latest inspection result. This method is proven to be a proper method to be used as a maintenance program for ageing fixed offshore platforms in Indonesia.