2. ABSTRACT
Design & Analysis of Mechanical Systems plays a backbone Role of
success of particular Systems. The engineering design & Analysis process is a
multi-step process including the research, conceptualization, feasibility
assessment, establishing design requirements, preliminary design, detailed design,
production planning and tool design, and finally production.
C-Clamp Mechanical Systems, studied in this project has many
applications starting from bench to rocket science. in this project we taken a two
different material in consideration and find which one is preferable for the hold
the work piece under the clamping principle.
3. What is Clamping?
Once work piece is located, it is necessary to press it against locating
surfaces and hold it there against the force acting upon it. The tool Designer
refers to this action as clamping and the mechanisms used for this action are
known as clamps.
Clamping Principles
Clamp should firmly hold the work piece without distorting it.
Should overcome the maximum possible force exerted on work piece by using
minimum clamping force
Easy to operate
4. Types of Clamping
Mechanical Actuation Clamps
Pneumatic and Hydraulic Clamps
Vacuum Clamping
Magnetic Clamping
Electrostatic Clamping
Non Mechanical Clamping
Special Clamping Operations
5. C-CLAMP:
Name of this clamp is because of its “C” shaped body. C-clamp has a
fixed jaw on one end and screw type jaw on other. Adjusting the screw
closed the jaw and applies pressure.
C-clamp is use to hold two object flush together.
It is also use for carried out various operations on small job of wood
& metal like filing, finishing, axe saw cutting etc.
Clamps or G-clamps are typically made of steel or cast iron.
6. It is required to design a C-clamp for holding the jobs on the shop floor
limiting dimension of the job are as follows
Hmax =150 mm
Wmax =150mm
The maximum clamping force required to hold the job is 10kN. The
clamp is manually operated
PROBLEM SPECFICATION
7. Sr. no Name of the component quantity Material
1 C-frame 1 Cast-steel grade 26-52
2 Screw 1 Steel 45C8
3 Nut 1 Phosphor bronze grade-1
4 Handle 1 Steel 30C8
5 Thrust pad 1 Steel 30C8
6 Set screw 1 Commercial steel
7 Hexagonal nut 1 Commercial steel
8. Formula used in frame design and screw design
Z = 24,134 mm3
CALCULATION
𝑍 =
𝐵𝐻3 − (𝐵 − 𝑡)(𝐻 − 2𝑡)
6𝐻
=
[(48 × 603)
−( 48 − 12 16 − 24 ]
6 × 60
Two types of threads are popular for power screws- square and trapezoidal. In
applications like lead-screw of lathe, trapezoidal threads are use because wear is series
problem. The axial wear of trapezoidal threads is compensated by drawing the two
halves of a split type nut to gather.
9. RESULTANT STRESSES
σ1 = t1 – c2
= (0.189 − 1.367)
=-1.178 N/mm2
σ2 = t1 + t2
=0.189 + 1.367
= 1.556 N/mm2
From above we can see that σ 2 is greater than σ 1 so compare the
permissible stress with σ 2.Here, σ 2˂ σ [ c]
So, c-frame is safe in compression.
A = (H − 2t)t + 2(B × t)
= (60-24)12+2(48×12)
10. DESIGN OF SCREW ROD:
Here, the screw rod is subjected to the compressive stress so check the
rod in compression as under:
Formula uses in screw rod design
Hence σc, < σ [c ] so screw rod is safe in compression
σc = 95N/mm2
11. DESIGN OF CAP SCREW
In the cap screw area at the thread section is minimum hence; there is
possibility of failure in Compression so checking it in the compression:
Formula uses in cap screw design
σc = 44.06 N/mm2 Hence, σc < σ[c] so cap screw is safe in compression
12. DESIGN OF JAW
The jaw is also check in compression:
Formula uses in jaw design
σc = 32.28 N/mm2
Hence, σc < σ[c]
so cap jaw is safe in compression
13. DESIGN OF HANDLE
Formula uses in handle design
When we applied the effort p1 at the end of handle, it is
subjected to the bending. So check the handle in bending:
α = 4.666˚
tan ϕ = µ
ϕ = 5.711˚
14. Now, torque transmitted through screw rod:
Mt =17,854.14 N/mm2
The torque transmitted through the handle is same as in screw rod:
M
b = p * L = (100*270) N/mm2
Now, find the bending stress induced in handle due to effort p1 and compare it
with the permissible bending stress. As, per bending equation:
σ
b
=32Mb/πd
σb =100 N/mm2 d= 15 mm
Hence, σb < σ [b ] so handle is safe in bending.
In this whole design of c-clamp, we found that the dimensions which are
selected for modeling is safe in all the failures.
15. Object Name
Static Structural
(B5)
State Solved
Definition
Physics Type Structural
Analysis Type Static Structural
Solver Target
ANSYS
Mechanical
Options
Environment Temperature 22. °C
Generate Input Only No
MODEL AND ANALYSIS
16. Structural Steel > Constants
Density 7850 kg m^-3
Coefficient of Thermal Expansion 1.2e-005 C^-1
Specific Heat 434 J kg^-1 C^-1
Thermal Conductivity 60.5 W m^-1 C^-1
Resistivity 1.7e-007 ohm m
Aluminum Alloy > Constants
Density 2770 kg m^-3
Coefficient of Thermal Expansion 2.3e-005 C^-1
Specific Heat 875 J kg^-1 C^-1
24. RESULT AND DISCUSSION
In the project of C-clamp, we mainly consider the factor of
griping of workspace at load condition without failure
The whole design focuses on how the values of stresses
Here, the basic concept is established for choosing the best
material combination for given load
The above analysis is fully made of structural steel and
aluminum alloy
compared to both material structural steel had a good safer value
in all kind of analysis
The handle part and the thrust pad are become safer than the
structural steel, because the handle part more affected in the
aluminum alloy.
25. Function Aluminum alloy Steel
Stress value Min = 1.901 e05 pa
Max = 1.122 e10 pa
Min = 4.15 e04 pa
Max =1.05 e09 pa
Safety factor Min =2.27 e-02 Min =0.2381
RESULT AND DISCUSSION
26. REFERENCES
1) INTRODUTION TO MACHINE DESIGN – V.B BANDARI - TATA McGraw-
HILL EDUCATION PRIVATE LIMITED – 2ND
EDDITION
2) MACHINE DESIGN DATA BOOK, -2003 - PSG Publication.
3) MACHINE DESIGN – J.K GUPTA –EURASI PUBLISHING HOUSE (PVT.) LTD.
4) ANSYS WORKBENCH 14.0 FOR ENGINEERING DESIGNER
5) Djordje Vukelic, Uros Zuperl & Janko Hodolic “Complex system for fixture
selection, modification, and design” Int J Adv Manuf Technol
6) J. Cecil “A Clamping Design Approach for Automated Fixture Design” Int J Adv
Manuf Technol
