Final Project Ansys

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A Project of Aircraft Structure Analysis

Dept of Engineering and Technology

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FINAL PROJECT ( ANSYS)

Submitted by : MUHAMMAD HARIS MUNIR

DANIAL ALI

(BAT11343)

Date : 26/12/13

(BAT11362) Submitted to : Prof.IMTIAZ HUSSAIN


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Table of Contents Acknowledgement ................................................................................. 4

Executive Summary ................................................................................. 5

Ansys Mechanical APDL .............................................................................6


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ACKNOWLEDGEMENT

This project would not have been possible without the support of our professor. We wish to express our gratitude to his supervision, Prof. IMTIAZ HUSSAIN who was abundantly helpful and offered invaluable assistance, support and guidance. The knowledge about our project is really interesting and technical. During this project we learnt many new things and different aspects of structure analysis.


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EXECUTIVE SUMMARY

Structural analysis is important because it can evaluate whether a specific structural design will be able to withstand external and internal stresses and forces expected for the design. This in turn produces an electronic virtual working model for future design development. Structural analysis is the determination of the effects of loads on physical structures and their components. Structures subject to this type of analysis include all that must withstand loads, such as buildings, bridges, vehicles, machinery, furniture, attire, soil strata, prostheses and biological tissue. Structural analysis incorporates the fields of applied mechanics, materials science and applied mathematics to compute a structure's deformations, internal forces, stresses, support reactions, accelerations, and stability. The results of the analysis are used to verify a structure's fitness for use, often saving physical tests. Structural analysis is thus a key part of the engineering design of structures. The structure on which we have to analysis was a double joint composite material structure. We have used ANSYS software for this job and end up with certain results.


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ANSYS MECHANICAL (APDL) INTRODUCTION Structural analysis solutions from ANSYS provide the ability to simulate every structural aspect of a product, including linear static analysis that simply provides stresses or deformations, modal analysis that determines vibration characteristics, through to advanced transient nonlinear phenomena involving dynamic effects and complex behaviors. All users, from designers to advanced experts, can benefit from ANSYS structural analysis solutions. The fidelity of the results is achieved through the wide variety of material models available, the quality of the elements library, the robustness of the solution algorithms, and the ability to model every product — from single parts to very complex assemblies with hundreds of components interacting through contacts or relative motions.

PROBLEM GIVEN

SCOPE OF WORK    



A brief study of composite materials, their applications, design parameters involved. Composite material (Carbon-epoxy, Kevlar-epoxy, Glass-epoxy) Ply orientation (0,15,30) Staking sequence in composite plate (All zero, 0/15/0/15…, 0/ 30/0/30…, 0/0/15/15/0/0/15…., 0/0/30/30/0/0/30…., bottom five zero and above top 15/30)


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DRAWING MODELING

DATA GIVEN Part A: Metallic plates”

“

Part B:

Part C:

“Composite plates”

“Pins”

Material =

MS

Thickness =

10 mm

Dia =

Thickness =

3 mm

Length =

100 mm

Maximum two rows

Length =

82 mm

Width =

50 mm

Width =

50 mm

Number of plies = 10


4 mm

Applied force = 1kN

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BASIC DRAWING Firstly

I

have

divided

the

basic

drawing,

after

that

I’v

selected

option

PREPROCESSORMODELINGCREATE AREASRECTANGLE-> 2 corner

I made two rectangles which are the skin of aircraft. Then I made two more rectangles for patch. Then I extruded the 4 rectangles along normal axis 50 mm lengths. The basic drawings was ready.


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SUBTRACTION OF RIVETS Then I made circles on the surface of the joint to make space for rivets. I made circles and extruded. Then I subtracted that extruded holes from the joint. We subtract the holes so that we can define rivets in those holes.


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RECIRCLE After subtraction, I made the circle again on the already hollow holes and extruded. These again made extruded circles represents the rivets.

Element Type After filling the holed with rivets, I defined the element type. Here, two types of element are. One of composite and other rivets and patch plates are of steel. So I selected solid186 for steel and solid46 for composite material.

Real Constant After material definition, I defined the real constant for solid46 and I defined the layers of composite material which are 10 of 1 mm thickness. I also defined the layers orientation which was 15, 30 and 45. These angles of layers give optimum strength to the composite material in all directions.


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Element Properties After real constant, I def ined the material properties for composite and steel. For composite I’ve selected the orthotropic in solid46 and for steel, isotropic in solid186. The properties values are given in the start of this report. I define these values so that software can understand in which direction and as a whole the strength of material.

MESHING After this i selected PREPROCESSOR MESHINGMESH TOOL and select the option volumes and select all, we will get the following drawing as meshing. I do meshing so that the structure is divided in infinite parts and analysis will be better. After analysis on each part, the software will differentiate these results and give accurate value.


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MOVE PINS

I moved the pin out of the structure so that i can define contact of pin and the holes easily. If the pins are in the holes then contact pair is difficult to define.


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CONTACT PAIR

I defined contact pair so that software can understand that these surfaces are in contact, not fixed.


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FORCES APPLY Now we have to apply force on key points of all external sides .We select SOLUTIONDEFINELOADS APPLYSTRUCTURALFORCE/MOMENT KEYPOIN T. After applying we will get the following figure.

We give external forces to the structure for analysis. These forces can deform the structure if the structure is weak.


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SOLUTION IS DONE After applying forces we have to done its solution for this purpose we select SOLUTIONSOLVECURRENT LS According to the given data and follow all steps correctly the message must be shown on screen SOLUTION IS DONE The solution status is given in the table in picture.


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GRAPH OBTAINED

This graph tells that as the cumulative irritation number increases, the absolute convergence norm decreases. The cumulative irritation numbers is the term which tells that on a specific part, for how many times the analysis is applied. The absolute convergence norm tells that it is a non standard forces analysis. Non standard mean the forces are not in their standard units.


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DEFORMED/UNDEFORMED SHAPE GENERAL POSTPROCESSINGPLOT RESULTSDEFORMED SHAPE DEFORMED+UNDEFORMED

This shape tells us that after deformation, how our structure will look like. How much our structure will bend.


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VON MISES STRESS Von Mises stress is widely used by designers, to check whether their design will withstand given load condition. Von mises stress is considered to be a safe haven for design engineers .Using this information an engineer can say his design will fail, if maximum value of Von Mises stress induced in the material is more than strength of the material. It works well for most of the cases, especially when material is ductile in nature.

EXAMPLE FOR UNDERSTANDING


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VON MISES STRESS GENERAL POSTPROCESSINGPLOT RESULTSCONTOR PLOTELEMENT SOLUTIONSTRESSVONMISSES

This analysis tells that on a particular area, how much force is present. The forces range is given in different colors. If at any particular area is red, this tells that at that area maximum force is present. If the whole structure is red then this cannot be manufactured as It will damage earlier.


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MAXIMUM STRESS


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LOG FILE UNDERSTANDING


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REFERENCES (1) http://www.ansys.com/Products/Simulation+Technology/Structural+Analysis


Final Project Ansys

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