“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 subassemblies.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.

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
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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)
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IJMET
© I A E M E

2. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print),
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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),
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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),
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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

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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),
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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.

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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.)

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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

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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),
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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),
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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),
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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

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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

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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

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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.
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[1] Robort.D.Cook, Davis S Malkus, Michael E Plesha: Concepts and applications of Finite
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[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.
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[8] John Anderson Jr: Fundamentals of Aerodynamics, 4th
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