scholarly journals The Usage of Alternative Materials to Optimize Bus Frame Structure

Symmetry ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1010 ◽  
Author(s):  
Tautvydas Pravilonis ◽  
Edgar Sokolovskij ◽  
Artūras Kilikevičius ◽  
Jonas Matijošius ◽  
Kristina Kilikevičienė
Keyword(s):  
Dynamic Properties ◽  
Steel Structure ◽  
Frame Structure ◽  
Structural Elements ◽  
Resonant Frequencies ◽  
Centre Of Gravity ◽  
Alternative Materials ◽  
Structural Frame ◽  
Strength And Stiffness ◽  
Key Indicators

The strength and stiffness of the frame is one of the key indicators of vehicle structures. Insufficient stiffness causes vibration and noise, and is also less comfortable for both the passengers and the driver. Symmetry is required between the strength and comfort of the structural frame, which depends on vibration and noise. This article analyses the frame of the structure of a medium-sized passenger bus and its dynamic properties, when replacing materials of structural elements which do not affect the symmetry of the structure. The conducted theoretical and experimental modal analysis of the bus, allows for evaluating dynamic parameters and validating the theoretical model based on the experimental results. The optimization of the medium-sized passenger bus frame—by replacing the material of the ancillary frame elements with fiberglass—reveals that its dynamic characteristics change by up to 20%, comparing the values of the first three resonant frequencies with those of the steel structure. The obtained results show that replacing the material of ancillary frame elements with fiberglass, while maintaining the symmetrical arrangement of the elements in the structure, does not change the safety characteristics of the structure, reducing the mass of the frame by 11%, and shifting the coordinate of the centre of gravity vertically downwards, which is very important for stability, comfort and fuel consumption.

scholarly journals Analysis of the robustness of a steel frame structure with composite floors subject to multiple fire scenarios

2021 ◽  
pp. 136943322199249
Author(s):  
Riza Suwondo ◽  
Lee Cunningham ◽  
Martin Gillie ◽  
Colin Bailey
Keyword(s):  
Progressive Collapse ◽  
Three Dimensional ◽  
Steel Structure ◽  
Frame Structure ◽  
Worst Case ◽  
Collapse Resistance ◽  
Fire Scenarios ◽  
Element Approach ◽  
The One ◽  
Steel Frame Structure

This study presents robustness analyses of a three-dimensional multi-storey composite steel structure under the action of multiple fire scenarios. The main objective of the work is to improve current understanding of the collapse resistance of this type of building under different fire situations. A finite element approach was adopted with the model being firstly validated against previous studies available in the literature. The modelling approach was then used to investigate the collapse resistance of the structure for the various fire scenarios examined. Different sizes of fire compartment are considered in this study, starting from one bay, three bays and lastly the whole ground floor as the fire compartment. The investigation allows a fundamental understanding of load redistribution paths and member interactions when local failure occurs. It is concluded that the robustness of the focussed building in a fire is considerably affected by the size of fire compartments as well as fire location. The subject building can resist progressive collapse when the fire occurs only in the one-bay compartment. On the other hand, total collapse occurs when fire is located in the edge three-bay case. This shows that more than one fire scenario needs to be taken into consideration to ensure that a structure of this type can survive from collapse in the worst-case situation.

scholarly journals Comparative Evaluation of Concentric Bracing Systems for Lateral Loads on Medium Rise Steel Building Structures

2020 ◽  
pp. 124-130
Author(s):  
Sisaynew Tesfaw Admassu
Keyword(s):  
Lateral Displacement ◽  
Level Structure ◽  
Lateral Load ◽  
Frame Structure ◽  
Lateral Stiffness ◽  
Building Structures ◽  
Steel Buildings ◽  
Lateral Strength ◽  
Strength And Stiffness ◽  
Bracing System

To resistance, the lateral load from wind or an earthquake is that the reason for the evolution of varied structural systems. Because, when a medium or any multi-level structure is exposed to horizontal or torsional deflections under the action of seismic burdens. Lateral stiffness is a major consideration in the design of the buildings. In addition to this, many existing steel buildings and reinforced concrete buildings for which the weak lateral stiffness is the main problem; should be retrofitted to conquer the insufficiencies to resist the lateral loading. Lateral load resisting systems are structural elements providing basic lateral strength and stiffness, without which the structure would be laterally unstable. The unstable nature of the structure is solved by the fitting arrangement of bracings systems. A bracing system is that forms an integral part of the frame. Thus, such a structure has to be analyzed before arriving at the best type or effective arrangement of bracing. Bracing is a highly effective strategy of resisting lateral forces in a frame structure. In this document, a ten-story building with incorporated bracing systems is analysed using ETABS 2016 analysis software as per Eurocode and Ethiopian Building Code Standards (EBCS). Then, the lateral displacement is evaluated under each of the bracing types.

Fast Characterization of Silicon Membrane Structures by Laser-Doppler Vibrometry

2007 ◽  
Vol 1052 ◽  
Author(s):  
Ronny Gerbach ◽  
Matthias Ebert ◽  
Joerg Bagdahn
Keyword(s):  
Dynamic Properties ◽  
Laser Doppler ◽  
Mode Shapes ◽  
Defect Structures ◽  
Silicon Membrane ◽  
Membrane Structures ◽  
Unknown Parameters ◽  
Laser Doppler Vibrometry ◽  
Resonant Frequencies ◽  
Micromechanical Structures

AbstractMicromechanical structures were investigated nondestructively via laser-Doppler-vibrometry to determine defect structures. Therefore, silicon membrane structures were characterized by their measured resonant frequencies and mode shapes. The influence of defects on the micromechanical structures is shown on the measured dynamic properties. Defect samples were indentified on the basis of the ratios of measured resonant frequencies and the quantified comparison of mode shapes without an identification of unknown parameters. The investigations showed that a fast determination of defect structures is possible by measured dynamic properties.

Strengthening and Retrofitting of Motín de Oro II Bridge in Mexico

2020 ◽  
pp. 193-209
Author(s):  
Jose M. Jara ◽  
Bertha A. Olmos ◽  
Guillermo Martínez
Keyword(s):  
Material Properties ◽  
River Flow ◽  
Dynamic Properties ◽  
Flow Characteristics ◽  
Ambient Vibration ◽  
Structural Elements ◽  
Box Girder ◽  
Prone Area ◽  
Scour Protection ◽  
Ambient Vibration Measurements

This chapter presents the studies conducted to retrofit an existing bridge in a seismic prone area of Mexico. The Motín de Oro II Bridge was built in the 1970s with a continuous box girder superstructure and wall-type substructure. From the 1970s to nowadays, the design truck loads in Mexico have been substantially incremented and many bridges built in that period have required to be evaluated and, in some cases, rehabilitated and retrofitted. Firstly, the study presents the results of visual inspections of all parts of the bridge and a description of the preliminary studies conducted to determine the material properties, to evaluate the river flow characteristics and to calculate the scour depth. Secondly, the chapter discusses the initial structural analyses of the bridge subjected to the original gravitational and seismic loads and to the current loads before the intervention. These analyses allow to select the structural elements that require to be retrofitted and the best strategy to follow. Finally, the study presents results of the numerical retrofitted model and the experimental assessment of the dynamic properties based on ambient vibration measurements. Additionally, the scour protection and the general construction procedure are also described.

Structural Comparison and Project Cost Analysis on Two Kinds of Frame Structures

2012 ◽  
Vol 193-194 ◽  
pp. 1197-1200
Author(s):  
Zhong Min Liu ◽  
Xue Hua Liu ◽  
Jing Ji
Keyword(s):  
Reinforced Concrete ◽  
Concrete Structure ◽  
Steel Structure ◽  
Development Trend ◽  
Economic Benefits ◽  
System Structure ◽  
Frame Structure ◽  
Reinforced Concrete Structure ◽  
Project Cost ◽  
Advantages And Disadvantages

This article introduces two kinds of frame structure system structure for steel structure and reinforced concrete structure, analyzes the similarities and differences in the structural properties, structural occupied area, time limit for a project, project cost and comprehensive economic benefits and other aspects. The advantages and disadvantages of them are analyzed, and the engineering cost is compared and analyzed. Results show that the steel structure has more the advantage than reinforced concrete structure, and it is development trend of factories and high-rise building in the future.

The Structure of the Performance that Resist the Static Wind on the Reinforced of Steel Structure

2012 ◽  
Vol 193-194 ◽  
pp. 1109-1112
Author(s):  
Li Ming Wu ◽  
Xiao Liang Luo ◽  
Zi Jian Wang
Keyword(s):  
Reinforced Concrete ◽  
Steel Structure ◽  
Internal Force ◽  
Frame Structure ◽  
Reinforced Concrete Frame ◽  
Wind Resistance ◽  
Concrete Frame ◽  
Building Model ◽  
Finite Element Software ◽  
Reinforced Concrete Frame Structure

Taking a 5-story reinforced concrete frame structure on the transformed 3-layer steel frames for an example, use finite element software ANSYS to reformation as a whole building model under static wind load changes for comparative analysis of internal force and displacement of the corresponding node. Analysis results show that in the transformation of steel on reinforced concrete frame structure, should fully take into account the structural stiffness change on construction of the overall effect of wind resistance, so that the transformation of the steel concrete frame structure more reasonable.

FEM Analysis of Cylindrical Structural Elements under Local Shock Loading

2014 ◽  
Vol 566 ◽  
pp. 499-504 ◽  
Author(s):  
Leopold Kruszka ◽  
Yu.S. Vorobiov ◽  
N.Yu. Ovcharova
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Strain State ◽  
Shock Loading ◽  
Dynamic Properties ◽  
Fem Analysis ◽  
Finite Deformations ◽  
High Rate ◽  
Structural Elements ◽  
Stress Strain

High rate deformations of structures cylindrical elements are considered 3D formulation. Elastic-plastic finite deformations and dynamic properties of material take into account. The problem become geometrically and physically nonlinear and finite element method is used. The numerical analyses of dynamics stress-strain state of real structures elements is executed.

Dynamic Characteristics of a Wood Frame Structure: (II) the Effect of Artificial Damage

2013 ◽  
Vol 671-674 ◽  
pp. 921-926
Author(s):  
Hai Ling Xing ◽  
Dong Sheng Yao ◽  
Song Tao Xue
Keyword(s):  
Dynamic Properties ◽  
Damping Ratio ◽  
Frame Structure ◽  
Modal Parameter ◽  
Hilbert Huang Transform ◽  
Artificial Damage ◽  
Identification Technique ◽  
Wood Frame ◽  
Frequency Changes ◽  
Vibration Tests

A full-scale, three-storey wood frame structure had been tested in-situ to investigate the changes of dynamic properties due to artificial damage. Beams and braces of the test structure were removed, to simulate damage, and then reassembled, to simulate rehabilitation. Free vibration tests were performed during every stage of the tests. The natural frequencies and damping ratios were obtained using modal parameter identification technique based on the Hilbert-Huang Transform. It is shown that, when the structure is damaged or rehabilitated, the natural frequency changes in accord with the structural stiffness in general while the damping ratio varies irregularly.

scholarly journals Assessment of technical condition and repair of steel structure elements on the example of fire damage in a warehouse building

2019 ◽  
Vol 284 ◽  
pp. 02001
Author(s):  
Andrzej Ambroziak ◽  
Paweł Piotrkowski ◽  
Tomasz Heizig
Keyword(s):  
Steel Structure ◽  
External Source ◽  
Technical Condition ◽  
Actual Condition ◽  
Test Results ◽  
Structural Elements ◽  
Site Investigations ◽  
Laboratory Test Results ◽  
Repair Procedure

The paper analyses a case study on the structural assessment of warehouse building partially damaged by fire caused by external source (fire of lorries close to the building). The authors focus on the site investigations and laboratory test results prior to assessing actual condition of the structural elements. Both strengthening concept and repair procedure of a steel column are addressed here. A short literature survey in the paper regards fire damages and its impact on the entire structural systems and its members.

Sign in / Sign up

Export Citation Format

Share Document