Brief introduction of soft muscle tissues and compression test of bovine muscle tissue

1. GROUP ME7
SHUBHAM SHRIVASTAVA 2011225
VIVEK KUMAR 2011237
RAVI MEENA 2011213

2.  Muscles provide structural support to the bones and
modify the impact between bones and external loads on
the body.
Muscle tissues account for about 40-50% of body mass
and an understanding of its deformation behavior is very
important for human body impact biomechanics research.
In the project results of compressive loading of freshly
slaughtered Ovine muscle tissue sample using a UTM
testing rig is reported.

3. 50%
15%
16%
15%
4%
BIOLOGICAL COMPOSITION
Soft Muscle Tissues
Bones
Skin
Fat
Others
% of Human Body Weight

4.  The muscular system is responsible for
the movement of the human body.
 Attached to the bones of the skeletal
system are about 700 named muscles
that make up roughly half of a person’s
body weight.
 Muscle tissue is also found inside of
the heart, digestive organs, and blood
vessels.

5.  A group of tissues which binds, supports and
protects our human body and structures such as
organs is soft tissue.
 TENDON AND LIGAMENT
 Tendons act as muscle to bone linkage while
Ligaments join one bone to the another one.
 They are subjected to tension and there primarily
purpose is to transmit the load.
 In complex joints such as the knee, ligaments help
to stabilise the joint (preventing undesired
motions).
 These are highly elastic material and very strong in
tension.

6.  CARTILAGE AND FASCIA
 Cartilage is a flexible connective
tissue found in the joints between bones,
the rib cage, the ear, the nose etc.
 It is not as hard and rigid as bone but is
stiffer and less flexible than muscle.
 A fascia is a layer of fibrous tissue that
surrounds muscles, group of muscles, blood
vessels, and nerves.
 It binds some structures together, while
permitting others to slide smoothly over
each other.

7. COLLAGEN
 Collagen is the main structural protein of the various connective tissues
 It is the main component of connective tissues, making up 25% to 35% of the
whole body protein content.
ELASTIN
 Elastin is a protein in connective tissue that is elastic and allows many tissues in
the body to resume their shape after stretching or contracting.
 Elastin load-bearing tissue in the bodies of vertebrates and used in places where
mechanical energy is required to be stored.
 Only biological part which shows linear elastic behavior
KERATIN
 Fibrous structural protein making up the outer layer of human skin.

8. VISCERAL MUSCLE
 Controlled by the unconscious part of the brain, so known as involuntary muscle.
 Weakest muscle found inside of organs like the stomach, intestines, and blood
vessels.
 Also known as ‘Smooth Muscle’
CARDIAC MUSCLE
 Cardiac muscle is found only in the heart Tissues.
 It is also an involuntary muscle

9. SKELETAL MUSCLE
►Skeletal muscle is the only voluntary muscle tissue in the human body
►80-90 % of the muscles are skeletal muscles
►Every physical action that a person consciously performs (e.g. speaking, walking,
or writing) requires skeletal muscle.
►Most skeletal muscles are attached to two bones across a joint.
 The function of skeletal muscle is move parts of the body.

10. NONLINEAR VISCOELASTIC
►The stress strain curve is non linear and
during loading and unloading it follows
different paths.
►Soft muscle tissues shows time dependent
stress–strain behaviour.
►It shows different behaviour for different
value of strain rates.

11. INHOMOGENEOUS AND ANISOTROPIC
►It has the different behaviour in fiber and cross fiber direction.
Cross fiber direction Fiber Direction

12. CROSS LINKED STRUCTURE
►Soft tissues shows the cross link properties
like polymers.
►In polymers a cross-link is a bond that
links one polymer chain to another.
►In Soft tissues cross-linking occurs in
collagen fibers.

13. AGE
 Tissues becomes harder and less
elastic as we get older
 Different behavior for different age
soft tissue sample
SPECIES
 For different species the mechanical
behavior is different
 Porcine muscle tissue are stronger as
compare to ovine muscle tissue
STRAIN RATE
 If we increase the strain rate value we need
larger forces to get same deformation
PHYSICAL ENVIRONMENT
 Higher stresses are developed if the
temperature is decreased

14.  [Phase-I]: The stress-strain curve is
approximately linear and lower value of
force achieves large deformations.
 [Phase-II]: Collagen fibers tend to line up
with the load direction and gradually
elongate.
 [Phase -III]: The collagen fibers aligned
with one another in the direction in which
the load is applied. The straightened
collagen fibers resist the load strongly.

15. COMPRESSION TEST OF SOFT RUBBER
SPECIFICATION OF SAMPLE
Length of sample = 17.6mm
Width of sample = 17.34mm
Thickness of sample = 11.48mm
Cross section area = 305.184mm^2
Density = 1.41gm/cc

16. EXPERIMENTAL PROGRESS
Enlarged Fracture View of Sample

17. RESULTS
 Stress vs strain curve varies
approximately linearly up to the strain
limit of 0.18 and non-linear onward.
 Young’s Modulus- 1.32 Mpa
 Compressive Strength- 1.0467 MPa
Stress vs Strain Curve

18. COMPRESSION TEST OF SILICONE RUBBER
SPECIFICATION OF SAMPLE
Thickness of sample = 11.66mm
Diameter of cross section = 9.7 mm
Cross section area = 73.898 mm^2
Density of material = 1.21gm/cc

19. RESULTS
Stress vs Strain curve Stress vs stain varies approximate
linearly with strain till the value of
strain 0.343(mm/mm) but it is non-
linear onward.
 Young’s modulus is 2.969MPa.

20. COMPRESSION TEST OF SOFT MUSCLE TISSUE
SAMPLE SPECIFICATION
 Cubical freshly slaughtered muscle tissue of
dimension 2 x 2 x 1.5 (cm)
 Cross section area (A) = 4cm^2
 Thickness of the sample = 1.5cm
 Direction of loading = Lateral to muscle
fiber direction

21. EXPERIMENTAL SETUP
 Fixed the sample in UTM between two
acrylic sheets.
 Applied the load in transverse direction
(cross fiber direction).
 Value of strain rate 0.0056/s

22. RESULTS
 TRUE STRESS
(Nominal stress (1 + Nominal strain))
 TRUE STRAIN
Log (1 + Nominal strain)
 Young’s Modulus Range 12 KPa to
500 KPa
 Curve is non linear
-20
0
20
40
60
80
100
120
0 0.1 0.2 0.3 0.4 0.5 0.6
TrueStress(KPa)
True Strain (mm/mm)
True Stress vs True Strain Curve

23.  Soft muscle tissue is nonlinear, viscoelastic, anisotropic and
inhomogeneous material. It is a very soft material which is
incompressible.
 Cross section area of the sample varies considerably during the
experiment. So nominal stress vs strain curve and true stress vs
strain curves are different from each other from the beginning.
 The results for the nominal stress are not reliable for soft materials
like muscle tissue so we have to go for true stress and true strain to
study the behavior of soft muscle tissues.

24.  TRUE STRESS- STRAIN AND NOMINAL STRESS- STRAIN CURVE
-50
0
50
100
150
200
250
300
350
400
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
Stress(KPa)
Strain (mm/mm)
Nominal vs True
Nominal
TRUE

25.  Comparison with previous work in this field
-20
0
20
40
60
80
100
120
140
160
180
200
0 0.1 0.2 0.3 0.4 0.5 0.6
TrueStress(KPa)
True Strain (mm/mm)
True Stress vs True Strain
Our Experimental Result
Pietsch and B. Wheatley

26.  We did the ANSYS analysis of human femur and human leg like
model only by applying loads gradually and found out the results
for stress and strain behavior.
 These analysis can be further implemented and can be calculated
more precisely considering impact loading
 We can apply our study in the field of human body subjected to
impact modeling i.e. vehicle crash,
 For these applications we need to know a little about various cases
of impact loading.

27. ANSYS ANALYSIS
LOADING SPECIFICATION
FEMUR LEG MODEL

28. STRESS ANALYSIS

29.  We studied the mechanical properties of soft muscle tissues and
performed the compression test of Ovine muscle tissue on UTM.
 The stress–strain curve for soft tissue is time dependent so it shows
different stress-strain curves for different value of strain rates.
 Because of nonlinearity of the curve Hook’s law is not valid for soft
muscle tissues So there is no exact value for the young’s modulus
for muscle tissues but an approximate range can be defined.
 There is considerable change in the cross section of the sample so
nominal stress-strain values are not reliable. We have to go for True
stress-strain values to study the behavior of soft muscle tissues.