Salam and hi...
Let me share with all of u a little bit information about a method / analysis that I was used in completing my assignments when I did my Bachelor Degree in Engineering. The method that I mentioned before is the Finite Element Method (FEM). For mechanical engineering student, I'm sure that everybody know and already used this method and ANSYS software is always used to implement this method or analysis.
Finite
Element Method (FEM) or also known as Finite Element Analysis (FEA) was
developed by R. Courant in 1943.1 The finite element
method has become a common tool for engineering analysis. Initially developed
and used for static structural analysis, it now covers domains in mechanical,
civil and electrical engineering. Finite element analysis can be applied to
problems in the areas of statics and dynamics of structures, buckling, fluid
transport, heat transfer and electromagnetism.2
FEM consists of a computer model of a material or design that is stressed and analyzed for specific results. It is used in new product design, and existing product refinement. A company is able to verify a proposed design will be able to perform to the client's specifications prior to manufacturing or construction. Modifying an existing product or structure is utilized to qualify the product or structure for a new service condition. In fact, in case of structural failure, FEM may be used to help determine the design modifications to meet the new condition.1 Some examples of finite element method as shown in figure below.
FEM consists of a computer model of a material or design that is stressed and analyzed for specific results. It is used in new product design, and existing product refinement. A company is able to verify a proposed design will be able to perform to the client's specifications prior to manufacturing or construction. Modifying an existing product or structure is utilized to qualify the product or structure for a new service condition. In fact, in case of structural failure, FEM may be used to help determine the design modifications to meet the new condition.1 Some examples of finite element method as shown in figure below.
Heat transfer analysis on structure by using FEM
(Source:
www.noraneng.com)
Pressure
analysis on structure by using FEM
(Source:
www.umass.edu/mie/labs/mda/fea/fealib/goldstein/PROJECT.html)
In my assignment, I have given a task to analyze the short-span bridge connecting the
clinic of Faculty Dentistry in UITM Shah Alam by using the existing configuration. Bridge may be
classified by how the forces of tension, compression, bending, torsion and
shear are distributed through their structure. There are many types of bridges
such are beam bridge, arch bridge, truss bridge, and cable-stay bridge. In this
analysis, beam bridge will be the finite element model.
The strength of the bridge must be higher enough to accommodate the loads imposed on it. By doing finite element analysis, the determination of the effects of loads on bridge structure and their components can be predicted. Other than that, this structure analysis bring a specific knowledge in understanding the behavior of bridge structures, parameters affecting its response and also the ability to predict its response to all types of loading. The objectives of this assignment is to predict the behavior of the bridge structure, its strength, and displacements at certain loads and situations. The analysis of this bridge is actually wanted to find the strength and displacement analysis with the certain configuration for the maximum pedestrian load. Then, the aim of the study is also to develop finite element model of a bridge structure.
Bridge at clinic of Faculty Dentistry was support and connects with many type of beam like I-Beam, L-Beam and C-Beam. Note that, a beam is a horizontal structural element that is capable of withstanding load primarily by resisting bending. The bending force induced into the material of the beam as a result of the external loads, own weight, span and external reactions to these loads is called a moment. Then, finite element model of each beam have been defined by using ANSYS V5.7 software.
The displacement analysis then has been conducted to the bridge and the result is obtained.
Sources:
1. http://www.sv.vt.edu/classes/MSE2094_NoteBook/97ClassProj/num/widas/history.html
2. Wahyu Kuntjoro, "An Introduction to the Finite Element Method", Universiti Teknologi MARA, 2005.
The strength of the bridge must be higher enough to accommodate the loads imposed on it. By doing finite element analysis, the determination of the effects of loads on bridge structure and their components can be predicted. Other than that, this structure analysis bring a specific knowledge in understanding the behavior of bridge structures, parameters affecting its response and also the ability to predict its response to all types of loading. The objectives of this assignment is to predict the behavior of the bridge structure, its strength, and displacements at certain loads and situations. The analysis of this bridge is actually wanted to find the strength and displacement analysis with the certain configuration for the maximum pedestrian load. Then, the aim of the study is also to develop finite element model of a bridge structure.
Bridge at clinic of Faculty Dentistry was support and connects with many type of beam like I-Beam, L-Beam and C-Beam. Note that, a beam is a horizontal structural element that is capable of withstanding load primarily by resisting bending. The bending force induced into the material of the beam as a result of the external loads, own weight, span and external reactions to these loads is called a moment. Then, finite element model of each beam have been defined by using ANSYS V5.7 software.
Finite Element Model of I-Beam
Finite Element Model of C-Channel
Finite Element Model of L-Beam
After that, the finite element model of the bridge has been defined. The finite element model of the bridge consists of the nodes and elements. Node is a connection point while the element is the connection of two nodes.
Finite Element Model of the Bridge (consists of nodes & elements).
The size of the bridge is approximately
1772cm X 352cm (length x width). Assume that the size of 1 person stand on the
bridge is about 45cm X 45cm. So, the maximum persons can be located on the
bridge at one time are given by:
- Total area: 1772 x 352 = 623744cm2
- Area of one person (by assumption): 45 x 45 = 2025cm2
- Maximum person on bridge at one time: 623744 / 2025 = 308.0217 ≈ 309 persons.
- Assume that weight of 1 person = 60kg.
- Maximum weight on the bridge: 309 x 60 = 18540kg
- Therefore, maximum load on the bridge is: 18540 x 9.81 = 181877.4 N
The displacement result of the bridge (isometric view)
Side view
Related video of Finite Element Analysis for Bridge
(Source: http://www.youtube.com/watch?v=dEpxSfgq6vo)
(Source: http://www.youtube.com/watch?v=dEpxSfgq6vo)
Sources:
1. http://www.sv.vt.edu/classes/MSE2094_NoteBook/97ClassProj/num/widas/history.html
2. Wahyu Kuntjoro, "An Introduction to the Finite Element Method", Universiti Teknologi MARA, 2005.
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