Placement of Sensors in Operational Model Analysis Assignment Sample

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• Subject Name : Engineering

Design of Truss

Summary of Placement of Sensors in Operational Model Analysis

The research article is demonstrated for design, development and finite element analysis of truss structure, which uses for bicycle and pedestrian overcrossing. The truss bridge is a type of overcrossing where that connected elements of bridge in triangular manner. The truss is rigid and transfer load from the single point to wider area. Therefore, it is useful to ensure the structural strength of truss assembly before physical construction and installation using finite element method. the project is demonstrate truss design with 15000 x 10000 x 5000 mm dimension of truss using I-beam standard cross section, where as the truss bottom or desk is made from wooden material with 250 mm thickness. The finite element analysis performs using ANSYS application in order to study about behavior of truss. In this case, there are mainly three simulation perform using two distinct I-beam section. The dimension of I-beams are Euro code UB 127 x 76 x 13 mm and Euro code UB 152 x 89 x 16 mm respectively. There are mainly three simulations perform includes “static analysis”, “modal analysis” and “Harmonic analysis” simulation. The simulation provides structural behavior, vibration behavior and steady state sinusoidal response with varying load. The FEA results for both I-beam require comparing and justified, which one is more desirable under provided circumstances.

Table of Contents

Summery.

Introduction.

Project objectives.

Engineering Method:

Static structural analysis of Truss bridge with I-beam (152 x 89 x 16 UB & 127x 76x13)

Model Analysis of Truss Bridge with I-Beam..

Harmonic Analysis.

Results and discussion:

Modal Analysis:

Harmonic Analysis:

Conclusion:

References.

Introduction to Placement of Sensors in Operational Model Analysis

 Pedestrian/Bicycle overcrossings represent one of the most crucial elements of a community’s non-motorized transportation network. They are the critical links joining the areas separated by a variety of “barriers” like rail lines, rivers or highways. A truss bridge is a type of overcrossing where the connected elements of the bridge form triangular units. Trusses are rigid and transfer loads from single point to a wider area. As designing the elements of bridge factors includes cost, design life, deflections, loads, material, dynamic behavior and material have to analyze to ensure the safety and reliability of entire structure. For design consideration, there are mainly three types of loads require to consider viz, dead load, live load and moving load. The dead load due to weight of deck, self-weight of structure and railing supports [4]. The live load includes pedestrians, wind and cyclist. The moving load includes loading of moving service vehicle. In this report, the defined size of truss design using ANSYS application and perform simulation by assembled two distinct I-beam. The I-beam size and dimensions are different to each other and that is requiring evaluating in order to identifying which beam suitable for truss design. The FEA procedure and results outcome discussed in next section.

Project objectives

• To design and prepare two distinct geometry using standard I-section beam
• To prepare truss drawing using “ANSYS space claim” and evaluate using static structure analysis.
• To perform model and Harmonic analysis using ANSYS application in order to evaluate mode shape and frequency of truss and obtain steady state behavior of complete geometry.

Engineering Method

Usually, the product design is prepare by considering application and use of specific product. In this case, the truss design is prepare to connect two roads and allows passing pedestrian, bicycle and lightweight vehicles [6]. It is obvious that the truss should able to resist the static and dynamic load as people passes over the bridge. By considering actual working practice, it observes that the truss and pad ester bridge could induce static and vibrating behavior of machine component. In order to study about the dynamic behavior of truss and justified the bridge design is suitable or not under given circumstance, the following is provides “ANSYS simulation” study using software. In this case, the standard shape I-beam uses to perform simulation and obtain static and vibrating behavior [6].

In first stage, the product design geometry prepared using ANSYS space claim default application. The following figure provides the “isometric” view of truss bridge with 15000 x 10000 x 5000 mm dimensions.

The above geometry is prepared by considering “I-beam” arrangement and individual elements. As complete geometry prepared, further it is require assigning material to truss elements and flat plate, which make from wooden material [4].

Assign I-beam to each element and perform mesh operation in order to divide truss body into finite size and finite shape. The following figure provides the “mesh” geometry of truss body.

The above figure provides the mesh operation of entire segment. It is visible that the truss body separate by quad element equally. The numbers of elements are 312 and numbers of nodes are 520. There are two different size of I-beam use to perform finite element analysis through truss bridge geometry [3]. The following are discuss all three simulation, which perform through ANSYS application.

In first case, 152x89x16 mm I-beam uses to construct “truss geometry” and perform static simulation as following. Similarly, 127x 76x13 mm size I-beam uses to perform finite element analysis.

Static Structural Analysis of Truss Bridge with I-Beam (152 x 89 x 16 UB & 127x 76x13)

As discussed in previous two cases, the geometry prepares and meshes operation for both I-beam element and all three simulations are equal. The next step is to applied boundary and loading condition to truss bridge structure. As shown in following figure, the 5kPa pressure applied to wooden area and all four corners keep fixed end or the road ends keep fixed i.e. it may not allows to move in any direction[1].

As shown in above figure, the vertical or normal direction pressure applied by considering the dead load over the truss. The boundary conditions are important step in finite element analysis procedure, which allows putting the geometry in place by considering actual working conditions that means, the ANSYS simulation allows creating actual working environment of truss bridge before actual construction and installation[5]. This can save time, effort and cost of construction, installation and maintenance of any product. Therefore, the finite element analysis is useful and effective technique for product design, development and optimization. 

As shown in above figure, the external applied pressure is equal distributed throughout the segment of wooden desk of truss and both ends are fixing over the road span. This is final stage of FEA analysis, the next step is to plot diagram and discuss results and significant effect in product [8].

As discussed in previous case that there are two distinct I-beam uses to design “truss bridge”. Therefore, the product design geometry is similar for both case, but the beam should require replacing from existing I-beam and performing equal simulation with provided boundary conditions. The following is provides results of static structural analysis and discuss significant effect of performance outcome [7].

Model Analysis of Truss Bridge with I-Beam 

The model analysis performs in order find frequency and mode shape of structure. It observes in practical scenario consideration, that the bridge may create force vibration due to uneven pressure over the span of wooden deck. The range of frequency and mode shape gives guidelines to select specific size of beam and wooden deck material. In finite element analysis procedure, it is consider both ends of wooden deck and end I-beams are fixed and allows vibrating due to pressure and force. The result obtains from “model analysis is discussed in next season. It is notice that, mode shape and frequency obtain for both I-beam truss [8].

Harmonic Analysis

The harmonic analysis performs to obtain the steady state sinusoidal response to sinusoidal varying loads which acting at specific frequency [9]. In many cases, the load applied with the phase offset. The harmonic analysis and model analysis is characterizing the structure i.e. it is beneficial to use combine effort of both terms. The boundary and loading conditions for harmonic analysis is same as discussed in previous two cases. The performance output and frequency response provides significant result and range to select design parameters. The result obtain from harmonic analysis are discussed in next season.

Results and Discussion on 

1. Results comparison: static structural analysis

As mentioned in earlier case, the FEA analysis performs by placing I-beam (152x89x16 mm) and 127x 76x13 mm respectively. The following is provides results of static analysis and compare with each other.

Deformation:

As shown in above diagram, the displacement value in both marginally difference in “meter” unit. The maximum deformation occurs at the top of joint due to “stress concentration effect” and pulling effect due to gravitation force [2]. Therefore, it is recommend using high strength welding at join of each beam to avoid displacement and permanent plastic elongation. The next result, von-misses stress obtains under given circumstances.

Von-misses stress:

The above figure indicates the von-misses stress of “truss bridge” by considering equal boundary conditions in both cases. The maximum stress induce in 152 UB is 482.62 Mpa whereas the 482.52 Mpa stress induced on 127 UB I-beam placement. The material takes as structural steel or industrial steel in order to construct truss bridge. The yield limit of steel material is around 250-260 Mpa. This magnitude indicate the pressure or force induce over the truss bridge less than 250-260 Mpa may not elongate, but more than that it will start elongation and plastic deformation occur as increasing pressure[5]. The above diagram indicate the elongation occur due to external applied pressure or force in normal direction.

In static structural analysis, the deformation and von-misses stresses are important characteristics by considering strength and rigidity parameters.

Modal Analysis:

In theoretical case, it was difficult and complex to obtain mode shape and frequency more than 3. Therefore, it is more desirable to select and use ANSYS application in order to obtain different mode shape and frequency [4].

As discussed, the modal analysis performs using finite element analysis method and obtain mode shape and frequency range. The following table provides the deflection result with different mode shape and different I-beam section [6].

Table: Model Analysis of Truss beam

The above table provides modal analysis and results of truss beam as comparing with I-beam different segment. It is notice that, the maximum deflection occurs 152 x 89 x 16 UB I-section beam due to vibrating effect.

Harmonic Analysis

This analysis provides the effect of structure by experience of steady state response, which responsible for generating force or free vibration. It could be combine result of modal analysis and harmonic simulation. The following is provides the result obtain from simulation.

From harmonic analysis, there are mainly three important characteristic result obtained as shown in above diagram. The maximum deflection occur in 152 UB as 2.06 x 10−16mm, similarly, the maximum deflection observe in 127 UB is 2.73