STRUCTURAL ANALYSIS AND DESIGN OF A MOBILE MAST
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The document provides a detailed structural analysis and design of a mobile mast for a radar carrier vehicle, highlighting enhancements made by Gowra Engineering Technologies. It outlines the static analysis conducted, design modifications implemented, and the results obtained from using NASTRAN software for finite element modeling. Key modifications included changes to dimensions, material properties, and load cases to improve structural integrity and performance under various conditions.
![International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print),
ISSN 0976 – 6359(Online), Volume 5, Issue 9, September (2014), pp. 440-454 © IAEME
454
Summary of applied forces
Direction
Before modification structure
results
Before modification structure
results
applied
forces
reaction
forces
applied
forces
reaction forces
X-force (N) 6.589E-06 8.953E-06 6.300E-06 9.169E-05
Y-force (N) -3.038E+05 3.0E+05 -3.019E+05 3.019E+05
Z-force (N) -8.21E+03 8.02E+03 -8.641E+03 8.641E+03
X-moment (N-mm) -1.85E+08 1.69.05E+08 -2.05E+08 2.05E+08
Y-moment (N-mm) 3.008E+07 -2.88E+07 3.338E+07 -3.338E+07
Z-moment (N-mm) -8.127E+08 7.989E+08 -8.667E+08 8.667E+08
CONCLUSION
The Structural Analysis has been carried out for different load cases to find out the stress
contour plots; from this task first we carried out the Design improvements. The FE Model and
carrying out the additional analysis. In Additional Analysis, we added the gust load for different
directions by using different load cases has to be made.
In our project we have done the structural analysis for a 10 m MAST. We have performed a
static analysis at different conditions with a gust load. Structural analysis, we analyze the forces and
momentum of MAST. By observing the results, by changes done in the design of MAST we get
MAST more stable conditions and equilibrium. When comparing to privies loads force and
momentums are more advantageous to MAST.
REFERENCES
[1] Robort.D.Cook, Davis S Malkus, Michael E Plesha: Concepts and applications of Finite
element Analysis, 3rd
Ed, John Wiley and Sons.
[2] W.C.Young, R.G.Budynas: Roark’s Formulas for Stress and Strain, 7th
Edition, McGraw Hill.
[3] R.S.Khurmi, J.K.Gupta: A text Book of machine Design for Design Methodology.
[4] William J Anderson: MSC Nastan is a comprehensive simulation solution for the test.
[5] Rao V Dukkipati, M A Rao, Rama Bhat (2000): Computer Aided Analysis and Design of
machine elements, New Age international publishers.
[6] R.D.Cook (1995): Finite Element modeling for stress Analysis, John Wiley and Sons.
[7] T.J.R. Hughes (2000): The Finite Element Method, Linear Static Analysis, Dover Publications.
[8] John Anderson Jr: Fundamentals of Aerodynamics, 4th
Edition, McGraw Hill.
[9] Amir Javidinejad, “Structured Teaching of Machine Design for Future Design Engineers”,
International Journal of Mechanical Engineering & Technology (IJMET), Volume 3, Issue 2,
2012, pp. 120-127, ISSN Print: 0976-6340, ISSN Online: 0976-6359.
[10] N. Rishi Kanth, Dr.C.V.Mohan Rao and G. Yedukondalu, “New Method in Predictive
Maintenance of a Machine”, International Journal of Mechanical Engineering & Technology
(IJMET), Volume 3, Issue 1, 2012, pp. 142-149, ISSN Print: 0976-6340, ISSN Online:
0976-6359.](https://image.slidesharecdn.com/structural-analysis-and-design-of-a-mobile-mast-160218110933/85/STRUCTURAL-ANALYSIS-AND-DESIGN-OF-A-MOBILE-MAST-15-320.jpg)
STRUCTURAL ANALYSIS AND DESIGN OF A MOBILE MAST
- 1. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print), ISSN 0976 – 6359(Online), Volume 5, Issue 9, September (2014), pp. 440-454 © IAEME 440 STRUCTURAL ANALYSIS AND DESIGN OF A MOBILE MAST Siva Krishna.N1 , Amara Nageswara Rao.N2 1, 2 (Department of Mechanical Engineering, Nimra Institute of Science & Technology/jntuk, Jupudi Village, Krishna Dt A.P, India) ABSTRACT “Mobile mast for The Radar carrier Vehicle”, the working object is taking the images and giving the information to costal security services. This FE Assembly has the different sub- assemblies. Those names are Aerial Antenna Assembly, Aerial rotary Assembly, and Azimuth drive Assembly, Chassis & Sub frame, 4-Bar mechanism and Palette without riggers. The total Wight of this model is 30.590 tones. This FE Model can be configuration into two FE Models. These are Deployed 0 Degrees and Deployed 90 Degrees.For the static analysis in the deployed condition, the assembly rests on outriggers. For several models, the outrigger-bases were modeled as “clamped”. This is a reasonable assumption when the dead-weight of the model acts in the “Y” direction. The Structural Analysis and Design has been carried out for contrast loads to find out the displacement and stress contour plots; we can do FE Modeling, materials, physical properties, Boundary conditions and Loading conditions and Load steps .After completion of load steps we can go for run model by using Nastran tools. The Nastran solver can be generated. The post processor can be used for viewing the animation results and take the displacement and Stress contour plots. Keywords: Design Modifications and Structural Analysis, Radar Carrier Vehicle, Nastran. INTRODUCTION “MAST” means multi axis simulation table, mast having the multi degree of freedom and Simultaneous multi-axis motion. It is a very flexible, reliable, fast orientation changing table. General applications of a mast areMilitary Applications, HomelandSecurity, Law-Enforcement Applications, Intelligence Gathering Applications, Research& Scientific Applications, Security& Surveillance Applications, Border Security Applications, Commercial Applications and Data Collection/Sensors. INTERNATIONAL JOURNAL OF MECHANICAL ENGINEERING AND TECHNOLOGY (IJMET) ISSN 0976 – 6340 (Print) ISSN 0976 – 6359 (Online) Volume 5, Issue 9, September (2014), pp. 440-454 © IAEME: www.iaeme.com/IJMET.asp Journal Impact Factor (2014): 7.5377 (Calculated by GISI) www.jifactor.com IJMET © I A E M E
- 2. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print), ISSN 0976 – 6359(Online), Volume 5, Issue 9, September (2014), pp. 440-454 © IAEME 441 Background GOWRA ENGINEERING TECHNOLOGIES PVT. LTD. Has designed a 10m mobile mast for the Radar Vehicle. Preliminary analysis of this design have been carried out by GOWRA ENGINEERING TECHNOLOGIES PVT. LTD. As a part of the design activity, undertook the tasks of further improvement of the model and carrying out additional analysis. This report covers the first phase of this activity, the models for the static analysis and the results of these analysis. Given the availability of Nastran models of the preliminary analysis, and the unavailability of 3D CAD models, the selected approach was as follows: a) Treat the GOWRA ENGINEERING TECHNOLOGIES PVT. LTD. Nastran models as the starting point b) To verify these models, and note areas of potential improvements and / corrections c) Create “improved” models incorporating these improvements / corrections d) Perform analysis and report the results For step 2, the models were reviewed against assembly drawings supplied by GOWRA ENGINEERING TECHNOLOGIES PVT. LTD., and further discussed with them. The selected modeling approach was the outcome of these discussions. With respect to step 3, note that the number of elements to be used consists of conducting component level analysis with different mesh densities and evaluating the change in deformation under a gravity load. Based on these studies, suitable element densities were selected for each component. Further, correctness of the assembly models was verified by applying gravity loads along each of the X, Y and Z directions to check that element connectivity was correct. These results too, are not included in this report. However these load cases are included in the models delivered to them. With respect to Step 4, several load cases are included in the scope of this project. These include linear static analysis. This report covers the static analysis, including different cases. The load cases are summarized in the relevant sections below. Reference Model
- 3. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print), ISSN 0976 – 6359(Online), Volume 5, Issue 9, September (2014), pp. 440-454 © IAEME 442 Design Modifications 1. Diameter of the cylindrical pads in-between the azimuth and palette were increased to 150 mm from 75 mm and the position was adjusted so as to represent their pattern position in drawing. The cylindrical pads of 75mm Diameter The cylindrical pads of 150mm Diameter 2. Gussets were added on the upper link and lower link near the cross-member near the Pylon side. The dimensions of the gussets are 200 x 200mm and thickness of the gusset plate is 12mm. Upper and lower-link before adding gussets Upper and lower-link after adding gussets
- 4. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print), ISSN 0976 – 6359(Online), Volume 5, Issue 9, September (2014), pp. 440-454 © IAEME 443 3. Gussets were added to Pylons in order to minimize the stresses in the Driver side of pylons regions. The dimensions of the Gussets are 62 X 90mm with Thickness =20mm. The Pylon plate’s extension material has been removed near the Gussets. Pylons before adding gussets Pylons after adding gussets 4. Azimuth Base plate thickness has been updated to 20mm, 3mm from 16mm, 8mm, and 3mm. T=16m m T=8mm T=3mm Azimuth Base before modification Azimuth Base after modification
- 5. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print), ISSN 0976 – 6359(Online), Volume 5, Issue 9, September (2014), pp. 440-454 © IAEME 444 5. The mass of 7.77 tons has been re-distributed over the front end of the Chassis as shown. The Mass distribution over-the The Mass Re-distribution over- Front End of Chassis the Front End of Chassis 6. Added vertical supports inside the Aerial Antenna Frame. The Aerial Antenna Frame before adding The Aerial Antenna Frame after adding Internal supports Internal supports
- 6. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print), ISSN 0976 – 6359(Online), Volume 5, Issue 9, September (2014), pp. 440-454 © IAEME 445 7. Added supports between the outriggers (in folded Condition) and Palette Showing the supports between the outriggers and the Palette FINITE ELEMENT MODELS Comparison between initial and final models: This section summarizes the Nastran models supplied by GOWRA ENGINEERING TECHNOLOGIES PVT. LTD. and the final modified models are The “reference” model contained 8, 48,434 elements and 7, 45,149 nodes. 61 mass elements 470 rigid link elements 416895 quadrilateral 4-noded shell elements 5135 triangular 3-noded shell elements 202435 4-noded tetrahedral elements 800 5-noded pentahedral elements 201010 8-noded hexahedral elements 108523 6-noded tetrahedral elements 3105-D elements The elements in the final models are as below: • Deployed condition: Zero-Degree Model: 1, 62,500 elements, 1, 61,250 nodes Ninety-Degree Model: 1, 62,435 elements, 1, 61,368 nodes Apart from corrections to some meshed components, the significant changes were as follows: a) Avoid usage of tetrahedral elements b) Reduce the number of elements used for flanges etc., since these are considered relatively stiff.
- 7. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print), ISSN 0976 – 6359(Online), Volume 5, Issue 9, September (2014), pp. 440-454 © IAEME 446 As detailed earlier, the elements of the final models were arrived at using convergence estimates. A direct-comparison between the number of elements in the reference model and those in the improved models can be misleading. For example, the reference models contained 1, 01,879 tetrahedral elements for the U-bolts, 1, 75,714 tetrahedral elements in “flanges”, 1, 09,008 elements in the path between the sub-frame and the vehicle chassis. These 3 components represent 51.38 % of the total elements in the model. In comparison, the palette and sub-frame contained 1, 15,765 elements (or 12.5% of the elements) in the reference model as against 85, 258 elements (or 49% of the elements) in the “improved” model. c) Avoid the use of rigid elements d) Ensure compatibility of element types and continuity in connections across components Note that the final models do not contain any tetrahedral or pentahedral. All elements are concentrated mass elements, 4-noded quadrilateral shell elements, 3-nodded triangular shell elements, 8-nodes hexahedral elements or 2-nodded beam elements. Further, the GOWRA ENGINEERING TECHNOLOGIES PVT. LTD. The models used Steel, Aluminum. The final models use Steel and Balata only. Material Properties All materials use linear constitutive models. Data used is as shown below Material Young's Modulus (E, MPa) Poisson's Ratio Density kg/mm3 Notes Steel 2.1e+05 0.3 7.83e-9 Steel 2.1e+05 0.3 2.4e-08 Used for some components to ensure weight of elements is consistent with weight of sub-assembly Steel 2.5e+04 0.310 5.9e-10 Steel 9.6e+04 0.300 3.2e-09 Aluminum 7.0e+04 0.3 2.7e-09 Balata 1300.00 0.400 1.1e-09 Estimated properties (supplied by Gowra Engineering Technologies Pvt. Ltd.)
- 8. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print), ISSN 0976 – 6359(Online), Volume 5, Issue 9, September (2014), pp. 440-454 © IAEME 447 Beam Cross-sections Some components were modeled using beam elements. The data used for these elements is as below: Section Name Type Data Density (kg/mm3) Notes U-bolt Circular, solid Dia = 19mm 7.90E-09 Sub-frame and chassis sub- assemblies are attached together with the help of U-bolts Hollow Beam Circular, hollow I.D=100mm, O.D=115mm 2.40E-08 Hollow Cylinder of Hydraulic Actuator Beam Circular, solid Dia =80mm 7.90E-09 Piston in the Hydraulic Actuator Beam Circular, solid Dia=30mm 7.90E-09 Part of a sliding Cylindrical rod in the Rotary frame Assembly Beam Circular, solid Dia=40.8mm 7.90E-09 Beam Circular, solid Dia=51.6mm 7.90E-09 Beam Circular, solid Dia=65.8mm 7.90E-09 Beam Circular, solid Dia=50mm 7.90E-09 Beam Circular, solid Dia=44.2mm 7.90E-09 Beam Circular, solid Dia=35.0mm 7.90E-09 Beam Circular, solid Dia=30.0mm 7.90E-09 Summary of weights and elements Sub-assembly Earlier Weight of mast (103 kg) Added Weight of mast (103 kg) Aerial Antenna Assembly 1.5854 1.6500 Aerial Rotary Assembly 1.0256 1.230 Azimuth Drive assembly 1.309 1.309 Chassis and sub-frame 14.468 14.468 Four-bar mechanism 1.3408 1.356 Palette with Outriggers 10.575237 10.577 Total 30.304 30.590
- 9. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print), ISSN 0976 – 6359(Online), Volume 5, Issue 9, September (2014), pp. 440-454 © IAEME 448 The load cases and forces are summarized in the table below: Fig.No. Configuration Restraints Forces 1 Deployed, 0 degrees Outriggers clamped Self-weight (gravity) 2 Deployed, 0 degrees Outriggers clamped Self-weight and 90 kmph gust load 3 Deployed, 0 degrees Outriggers clamped Self-weight and 120 kmph gust load 4 Deployed, 90 degrees Outriggers clamped Self-weight (gravity) 5 Deployed, 90 degrees Outriggers clamped Self-weight and 90 kmph gust load 6 Deployed, 90 degrees Outriggers clamped Self-weight and 120 kmph gust load RESULTS Case 1 Deployed, 0 degrees / Outriggers clamped / Self-weight (gravity) Deformed shape Stress Contours Fig.No 1: Isometric-View
- 10. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print), ISSN 0976 – 6359(Online), Volume 5, Issue 9, September (2014), pp. 440-454 © IAEME 449 Summary of results Direction Before modification structure results Before modification structure results applied forces reaction forces applied forces reaction forces X-force (N) 0 0 0 7.50E-05 Y-force (N) -2.980E+05 -2.980E+05 -3.001E+05 3.001E+05 Z-force (N) 0 0 0 -1.168E-06 X-moment(N-mm) -1.495E+08 -1.495E+08 -1.51E+08 1.51E+08 Y-moment (N-mm) 0 0 0 -3.645E-02 Z-moment (N-mm) -8.489E+08 -8.489E+08 -8.554E+08 8.554E+08 Case 2 Deployed, 0 degrees / Outriggers clamped / Self-weight and 90 kmph gust load Deformed shape Stress Contours Fig.No 2: Isometric-View
- 11. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print), ISSN 0976 – 6359(Online), Volume 5, Issue 9, September (2014), pp. 440-454 © IAEME 450 Summary of results Direction Before modification structure results Before modification structure results applied forces reaction forces applied forces reaction forces X-force (N) .04E+03 -4.68E+035 4.86E+03 -4.860E+03 Y-force (N) -3.135E+ 052.887E+05 -3.011E+05 3.011E+05 Z-force (N) -6.631E-03 6.031E-03 -6.331E-03 6.332E-03 X-moment (N-mm) -1.71E+08 1.31E+08 -1.51E+08 1.51E+08 Y-moment (N-mm) -1.962E+06 1.662E+06 -1.962E+06 1.962E+06 Z-moment (N-mm) -9.003E+08 8.843E+08 -8.923E+08 8.923E+08 Case 3: Deployed, 0 degrees / Outriggers clamped / Self-weight and 120 kmph gust load Deformed shape Stress Contours Fig.no 3: Isometric-View
- 12. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print), ISSN 0976 – 6359(Online), Volume 5, Issue 9, September (2014), pp. 440-454 © IAEME 451 Summary of applied forces Direction Before modification structure results Before modification structure results applied forces reaction forces applied forces reaction forces X-force (N) 8.941E+03 -8.341E+03 8.641E+03 -8.641E+03 Y-force (N) -3.519E+05 2.519E+05 -3.019E+05 3.019E+05 Z-force (N) 5.712.E-06 -4.255E-06 6.E-06 -3.967E-06 X-moment (N-mm) -1.462E+08 1.558E+08 -1.51E+08 1.51E+08 Y-moment (N-mm) -3.889E+06 3.089E+06 -3.489E+06 3.489E+06 Z-moment (N-mm) -9.420E+08 9.0E+08 -9.210E+08 9.210E+08 Case 4 Deployed, 90 degrees / Outriggers clamped / Self-weight (gravity) Deformed shape Stress Contours Fig.No 4: Isometric-View
- 13. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print), ISSN 0976 – 6359(Online), Volume 5, Issue 9, September (2014), pp. 440-454 © IAEME 452 Summary of applied forces Direction Before modification structure results Before modification structure results applied forces reaction forces applied forces reaction forces X-force (N) 0 9.75E-05 0 9.48E-05 Y-force (N) -3.219E+05 2.7831E+05 -3.001E+05 3.001E+05 Z-force (N) 0 2.921E-05 0 2.633E-05 X-moment (N-mm) -1.54E+08 1.35E+08 -1.45E+08 1.45E+08 Y-moment (N-mm) 0 -1.531E-01 0 -1.374E-01 Z-moment (N-mm) -8.957E+08 8.237E+08 -8.597E+08 8.597E+08 Case 5 Deployed, 90 degrees / Outriggers clamped / Self-weight and 90 kmph gust load Deformed shape Stress Contours Fig.no 5: Isometric-View
- 14. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print), ISSN 0976 – 6359(Online), Volume 5, Issue 9, September (2014), pp. 440-454 © IAEME 453 Summary of applied forces: Direction Before modification structure results Before modification structure results applied forces reaction forces applied forces reaction forces X-force (N) -6.3E-03 6.248E-03 -6.33E-03 6.428E-03 Y-force (N) -3.211E+05 2.099E+05 -3.011E+05 3.011E+05 Z-force (N) -4.620E+03 4.460E+03 -4.860E+03 4.860E+03 X-moment (N-mm) -1.99E+08 1.59E+08 -1.79E+08 1.79E+08 Y-moment (N-mm) 2.477E+07 -1.277E+07 1.877E+07 -1.877E+07 Z-moment (N-mm) -8.936E+08 8.336E+08 -8.636E+08 8.636E+08 Case 6 Deployed, 90 degrees / Outriggers clamped / Self-weight and 120 kmph gust load Deformed shape Stress Contours Fig.no 6: Isometric-View
- 15. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print), ISSN 0976 – 6359(Online), Volume 5, Issue 9, September (2014), pp. 440-454 © IAEME 454 Summary of applied forces Direction Before modification structure results Before modification structure results applied forces reaction forces applied forces reaction forces X-force (N) 6.589E-06 8.953E-06 6.300E-06 9.169E-05 Y-force (N) -3.038E+05 3.0E+05 -3.019E+05 3.019E+05 Z-force (N) -8.21E+03 8.02E+03 -8.641E+03 8.641E+03 X-moment (N-mm) -1.85E+08 1.69.05E+08 -2.05E+08 2.05E+08 Y-moment (N-mm) 3.008E+07 -2.88E+07 3.338E+07 -3.338E+07 Z-moment (N-mm) -8.127E+08 7.989E+08 -8.667E+08 8.667E+08 CONCLUSION The Structural Analysis has been carried out for different load cases to find out the stress contour plots; from this task first we carried out the Design improvements. The FE Model and carrying out the additional analysis. In Additional Analysis, we added the gust load for different directions by using different load cases has to be made. In our project we have done the structural analysis for a 10 m MAST. We have performed a static analysis at different conditions with a gust load. Structural analysis, we analyze the forces and momentum of MAST. By observing the results, by changes done in the design of MAST we get MAST more stable conditions and equilibrium. When comparing to privies loads force and momentums are more advantageous to MAST. REFERENCES [1] Robort.D.Cook, Davis S Malkus, Michael E Plesha: Concepts and applications of Finite element Analysis, 3rd Ed, John Wiley and Sons. [2] W.C.Young, R.G.Budynas: Roark’s Formulas for Stress and Strain, 7th Edition, McGraw Hill. [3] R.S.Khurmi, J.K.Gupta: A text Book of machine Design for Design Methodology. [4] William J Anderson: MSC Nastan is a comprehensive simulation solution for the test. [5] Rao V Dukkipati, M A Rao, Rama Bhat (2000): Computer Aided Analysis and Design of machine elements, New Age international publishers. [6] R.D.Cook (1995): Finite Element modeling for stress Analysis, John Wiley and Sons. [7] T.J.R. Hughes (2000): The Finite Element Method, Linear Static Analysis, Dover Publications. [8] John Anderson Jr: Fundamentals of Aerodynamics, 4th Edition, McGraw Hill. [9] Amir Javidinejad, “Structured Teaching of Machine Design for Future Design Engineers”, International Journal of Mechanical Engineering & Technology (IJMET), Volume 3, Issue 2, 2012, pp. 120-127, ISSN Print: 0976-6340, ISSN Online: 0976-6359. [10] N. Rishi Kanth, Dr.C.V.Mohan Rao and G. Yedukondalu, “New Method in Predictive Maintenance of a Machine”, International Journal of Mechanical Engineering & Technology (IJMET), Volume 3, Issue 1, 2012, pp. 142-149, ISSN Print: 0976-6340, ISSN Online: 0976-6359.