1. ANALYSIS OF PRESSURE DISTRIBUTION IN
TRANSFEMORAL PROSTHETIC SOCKET
USING FINITE ELEMENT METHOD
Presented By,
JOSE MITON J G
Reg.No : 960321410010
M.E - Manufacturing Engineering
Department of Mechanical Engineering
Bethlahem Institute of Engineering, Karungal.
Guided By,
Mr. S. JAPDREW, M.E.,
Assistant Professor,
Department of Mechanical Engineering
Bethlahem Institute of Engineering, Karungal.
2. ABSTRACT
The intention of this project was to analyze prosthetic socket
of distinct materials and for different geometry for optimum
design solution by finite element analysis.
A modified three-dimensional finite element model of socket
was developed in workbench of solidworks Structural
Simulation to find out the stress distribution and
deformation.
A variety of materials were used for the analysis of the
socket like the optimization technique results showed that
the best optimal design of the prosthetic above knee socket
is PEEK, Perlon, Glass Fiber design.
3. This study focuses on the analysis of patellar tendon bearing
prosthetic sockets with integrated compliant features
designed to relieve contact pressure between the residual
limb and socket.
In this study, the numerical results of stress distribution
model of the prosthetic above knee socket showed that the
values of maximum stress according to Von-Misses criterion
results are increased with the increasing of temperatures.
The best designs results of the prosthetic above knee socket
are (94.64%) in PEEK compare with other materiel. The
procedure developed.
4. INTRODUCTION
The prosthetic socket is the connecting part between the
stump and the prosthesis, which is the important basis for
the function of the prosthesis.
The current prosthetic socket is difficult in meeting the
needs of amputees current, which is the main reason for
amputees abandoning their prostheses.
A prosthesis is a device designed to replace a missing part of
the body or to make a part of the body work better. Diseased
or missing eyes, arms, hands, legs, or joints are commonly
replaced by prosthetic devices.
7. Steps in Artificial limbs manufacturing
1. Measurement of the residual limb
2. Measurement of the body to determine the size required
for the artificial limb
3. Fitting of a silicone liner
4. Creation of a model of the liner worn over the residual limb
5. Formation of thermoplastic sheet around the model – This
is then used to test the fit of the prosthetic
6. Formation of permanent socket
7. Formation of plastic parts of the artificial limb 8. Creation
of metal parts of the artificial limb using die casting
9. Assembly of entire limb
8. PROBLEM IDENTIFICATION
The maximum percentage of failure was (55%) for the socket
made from plastic and the cause of failure was fracture where
as the minimum percentage was (15%) for the socket that
made from leather and the cause of failure was fracture.
Either for the height of the socket It was found that the
maximum percentage was (50%) for the socket of height with
knee level and the cause of failure was fracture, where as the
minimum percentage was (15%) for the socket of 1/3
distance between the knee and ankle joint and the cause of
failure was fracture also. Either for the motion of ankle joint it
was found that the maximum percentage was (60%) for the
socket of no motion and the cause of failure was fracture
where as the minimum value was (15%) for the socket of no
motion but the cause of failure was the shape change of the
socket.
9. OBJECTIVES
1. Improving the overall method for evaluation the fitting of
transfemoral prosthesis socket in all states includes:
standing posture and working.
2. Developing the three dimension (3D) model and finite
element model of residual limb includes: skin, fat, muscle
and bone; components of prosthesis include knee joint,
shank and feet.
3. Analysis the pressure beneath the foot prosthesis for
various light weight composite material during the gait of
transfemoral patients.
11. DESIGN CALCULATION
Assume the mass of the human body to be (75 kg), then to calculate
the force (F) that will act on the whole leg with (g=9.81 m/s2), and we
apply these values in this equation.
F = m x g
= 75 x 9.81
= 735.75 N
14. SOLIDWORKS SIMULATION
Step 1: Define Study
Step 2: Assign Materials
Step 3: Apply the Boundary Conditions (Free
Body Diagram)
Step 4: Mesh the Model
Step 5: Run the Analysis (Solve)
Step 6: View the Results
26. CONCLUSION
The lamination above knee prosthesis gave good results in
equivalent Von- Mises stress and the safety factor for
fatigue, and this led to the longer life design. Higher in
friction between above knee socket and stump by FEA
solution and prevent.
The above knee composite material socket model showed
that the fatigue safety factor for was which considered as
safe in design. The results summarized that integrating local
compliant features within socket wall can be an effective
method to distribute maximum stress areas and also to relief
contact pressure between the stump and socket.
27. The design solution obtained from the results can be used
as a reference to choose material for fabrication of socket in
developing countries like India, depending on the weight,
strength, cost and availability.
The socket made up of composite material may be
concluded the optimum solution for PEEK socket design.
The study explored further future scope for parametric
analysis, investigating the effects of socket stiffness,
rectification scheme and materials on the interfacial stress
distributions.
28. FUTURE SCOPE
The studies of this work would be more valuable and their
applicability could be expanded if the following works can
be supplemented: In the evaluation of interface pressure, the
works which need to perform or should be solved for the
better results are the material of soft tissue and the shape of
the residual limb.
However, the potential quality of life benefits of improving
the comfort of the residual limb–prosthetic limb interface
are substantial, for the life of the prosthetic limb user. From
a purely mechanical perspective.
