Stunt Safety_ Modeling and Effectiveness Assessment of Flame by hcj

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									    Stunt Safety: Modeling and Effectiveness Assessment of
          Flame Retardant Materials on Human Skin
                        BEE 453: Computer Aided Engineering:
                         Applications to Biomedical Processes
 Erica Carnrite, Patrick Deitemeyer, Chris Magnano, Jingye Wang, Howie Zheng

                                       May 11, 2004

I. Executive Summary

         This study focuses on the modeling of a flame-retardant material (Zel Jel) for its
application as a protective layer for stunt performers who are set on fire for movie scenes. We
begin with a 1-dimensional geometry to gain a basic understanding of the problem and to
perform a sensitivity analysis on the mesh and thermal conductivity of the gel (a value which we
were not able to obtain). For the 1-dimensional geometry, the skin is made sufficiently thick so
that it may be considered semi-infinite. On top of the skin are two layers: Nomex fabric and Zel
Jel. Using this geometry, we perform a simple heat transfer analysis using the GAMBIT/FIDAP
software package.

        The second phase of our study is to use Cornell’s body scanner to obtain an exact 3-
dimensional geometry of a human arm for analysis. The fabric and gel layers are then added
around the arm in the MAGICS software and the entire geometry is imported into the
GAMBIT/FIDAP software for analysis. The geometry acquisition was the most difficult aspect
of the study because such a process from the body scan to the finite element software had never
been done. The result of the 3-dimensional solution is then compared to the 1-dimensional
solution to determine whether our solution improves by utilizing the exact geometry. We
determined that the 3-dimensional geometry was not necessary to accurately model the problem,
but the most important result of our project was successfully obtaining a solution on our 3-
dimensional model. Below is an image of the complete 3-dimensional scan.
                                                    Stunt Safety, May 11, 2005                   263


II. Introduction and Design Objectives:

Background Information

        Have you ever wondered how stunt people survive being lit on fire during intense action
movie scenes? The secret is in the flame retardant materials that lie beneath their clothes. Using
an insulating layer of fabric combined with a fire retardant gel, they are able to withstand the
extreme heat from the flames without serious injury, at least for a short period of time.
According to Dr. Gary Zeller, inventor of Zel-Jel, the material we are modeling, the gel is an all-
natural polymer synthesized from pine gums and other nutrients that binds to the wearer's skin
and insulates for up to a whole minute; after use, it can be simply washed off because it is water-
based, and will actually add nutrients to the soil. It is important that this method of protection is
modeled accurately to insure the safety of the stunt performer.

Design Objectives

        For this study, we conducted our simulations in the Gambit and FIDAP software
package. The most useful results we obtained were how long the skin/fabric/gel combination
can be immersed within the flames before burning of the skin occurs. Using a transient analysis,
we are able to determine how long it is before a burn occurs. We began with a simple one-
dimensional analysis as shown below in order to establish the basics of solving our problem. We
then used the body-scanner to scan one of our group member’s arms and import it into FIDAP
for analysis. Our original plans for addition of complexities were as follows:

      Non-constant k-value for the gel (to represent its degradation).
      Without insulating fabric (to determine whether the gel can be safely
       used on unprotected areas of the body).
      Effect of different gels if information is available.
      Model burning as a mass transfer problem using the species equation [2].

Unfortunately, the volumetric meshing of the 3D scan of the arm proved to be quite difficult, and
we were unable explore any of these complications. Instead, we started with the 1D geometry
and did most of our analysis in that form. Once we were able to run a simulation on the 3D
geometry, we evaluated how similar it is to the 1D simulation.

       The following are assumptions we made for our analysis:
      Convection and body heat generation are negligible.
      The fire only affects the areas covered by fabric and gel.
      Mass transfer aspects of skin burning are neglected unless time permits.
                                                    Stunt Safety, May 11, 2005                   264


Schematics

1D:




Dimensions for 1D model

- These thicknesses also apply to the 3D scanned model -

Gel Thickness = 1/8”
Skin Thickness = Assumed to be semi-infinite so thickness is determined by trial and error.
Fabric thickness = 1 mm

3D:

All 3 layers- the inside (inside pink) is the arm itself, the middle layer (middle pink) represents
the outside of the fabric and the outer layer (teal) represents the outside of the gel.
                                                  Stunt Safety, May 11, 2005                 265


       This shows just the arm and the fabric layer.




        The difficulty that we ran into was in creating the actual volumes of these layers in
Gambit. For some reason, when just the layers are imported, Gambit doesn’t recognize the
volume of the individual layers. It takes the whole volume (including whatever is underneath)
into account. To overcome this problem we attempted to close the different layers. This was not
an easy task. To create the “ends” of the arm section, a section from another part of the body
scan were aligned on the ends and each of the triangles on the edges was then connected by
merging the vertices. The updated model is shown below.




        After attempting to create volumes using this closed model, it was determined that even
this updated model was giving us trouble.
                                                  Stunt Safety, May 11, 2005                 266


After sending our mesh to the software company twice, the issues preventing us from obtaining a
solution were finally resolved. The result was 9 volumes and 30 surfaces. The inner layer is the
arm, which has 1 volume and 3 surfaces. The two outer layers, which represent the fabric and
gel, each have 4 volumes (they are split into quarters about the radius). Below are two images of
this final working mesh.




                                        Isometric View




                                           End View
                                                 Stunt Safety, May 11, 2005                  267


III. Results and Discussion

The following is our preliminary 1-Dimensional Solution based upon property values for the
three materials given in Table 1 of Appendix A.




                      FIGURE 1: Temperature Contours at t = 5 minutes




               FIGURE 2: Time/Temperature plot at node 32, the center of the
                      gel-fabric interface (refer to 1D schematic)
                                                    Stunt Safety, May 11, 2005                   268




                      FIGURE 3: Time/Temperature plot at node 530, the
                       center of the skin surface (refer to 1D schematic)

Notes about the preliminary solution:

      Near the surface of the skin, the temperature actually drops initially! This is the result of
       the cold gel which is applied. The effect of the cooled gel is that it takes longer for the
       fire to affect it and cools the skin down initially, offering it more protection once the heat
       penetrates through the gel and fabric.

      Our solution works because as time passes, the heat does indeed penetrate into the fabric
       and skin. Although we may have overestimated the thermal conductivity of the gel, the
       other parameters will also change. Therefore, the possibility exists that our final solution
       will show slower heat penetration.
                                                    Stunt Safety, May 11, 2005                  269


       The following is our 3-Dimensional Solution:

Please Refer to Appendix C for additional mesh plots and a line contour of this solution




                                    Figure 4: Full 3D solution
                     At this magnification, it is impossible to see our results.
                     Only the initial and boundary temperatures are visible.




                                Figure 5: Magnified 3D solution

It is important to notice that the 3D solution actually behaves like the 1D solution in this area.
Keep in mind that this solution is only for 1 second so the effects of the 3D geometry may come
into effect at a later time. The time required to do such a calculation, however, was not practical
for this study taking into consideration the similarity to the 1D model.
                                                                            Stunt Safety, May 11, 2005          270


Sensitivity Analysis

      Mesh

                                              32.2
                                               32
            Temperature at Skin Surface (C)



                                              31.8
                                              31.6
                                              31.4
                                              31.2
                                               31
                                              30.8
                                              30.6
                                              30.4
                                              30.2
                                                     0   250   500         750         1000   1250       1500
                                                                     Number of Nodes

        FIGURE 6: Mesh Size Analysis for 60 (Blue Line) and 180 Seconds (Red Line)

        As part of our sensitivity analysis, we wanted to determine if the mesh size we are using
is too big or too small. Our original mesh size was 861 nodes. Increasing the number of nodes to
1281 did not significantly change the temperature at the skin surface at 1 minute or 3 minutes.
Reducing the mesh size to 270 nodes or 110 nodes causes the temperatures at the skin surface to
deviate from the values that were obtained with mesh size 861. This indicates that a mesh size of
861 is adequate for our simulation. In Appendix B are mesh plots and temperature plots at the
skin surface for different mesh sizes presented in the chart above.
                                                                    Stunt Safety, May 11, 2005           271


Thermal Conductivity of Gel

Since the thermal conductivity of the gel is the parameter that we are least sure of until we
measure the actual gel properties, we have started our sensitivity analysis there. The results are
presented in the graph below.


                                80


                                70


                                60
              Temperature (C)




                                50


                                40


                                30


                                20


                                10


                                 0
                                     0   0.02   0.04         0.06       0.08         0.1   0.12   0.14
                                                       Thermal Conductivity of Gel

 FIGURE 7: Gel Thermal Conductivity Analysis for 60 (blue line) and 180 Seconds (red line)



This data was taken at node #85. In the mesh we used, this node was near to the surface of the
skin at the center. Clearly, the thermal conductivity of the gel has an effect on the effectiveness
of the gel at later times. However, if the burning stunt only lasts for about a minute, the value for
the thermal conductivity of the gel has much less of an effect. The following graphs help
illustrate why this is so.
                                   Stunt Safety, May 11, 2005         272




FIGURE 8: Time/Temperature Plot  Thermal Conductivity = 0.13 W/m-K




FIGURE 9: Time/Temperature Plot Thermal Conductivity = 0.04 W/m-K
                                                    Stunt Safety, May 11, 2005                  273




         FIGURE 10: Time/Temperature Plot  Thermal Conductivity = 0.01 W/m-K

The final plot uses a thermal conductivity 1/10 that of the fabric. The interesting feature here is
that the temperature of the skin actually levels off below body temperature! This is intriguing
because stuntmen have reported actually feeling cold even while performing full-body burns.
The problem with this value for thermal conductivity is that it is unrealistic. The thermal
conductivity of air is approximately 0.04 W/m-K and the gel is likely to have a higher thermal
conductivity than that. Our initial explanation as to how this unrealistic thermal conductivity
models the reported situation was that, in reality, evaporation of the gel causes the cooling effect
on the stunt performer. However, after one of our group members spoke with Dr. Zeller (see
Section II), we were led to believe that this idea of evaporation was wrong because the water
actually binds to the skin. It seems, though, that some of the water at the surface of the gel could
still evaporate and keep the gel itself cool. Despite the confusing results of our research and our
sensitivity analysis, we still believe that the thermal conductivity is more likely to be lower than
higher.
                                                   Stunt Safety, May 11, 2005                 274


Difficulties and Realistic Constraints:

Economic Difficulties:

We discovered that not only is it impossible for us to purchase the gel due to our lack of
licensing, Zel Gel is sold only in 1-Gallon allotments, for prices around $500.00. Moreover,
since Zeller International is the only distributor of the gel, we are forced to only go through
them; fortunately, Dr. Zeller was going to provide us with pint-sized samples, but other factors
intervened, and this did not occur.

Property Issues:

     One problem with these results is our property values. While the bone and arm values are
accurate, as are the properties of the Nomex fabric, getting property values for the Zel Gel was
extremely difficult, and could be a paper in and of itself. After being unable to purchase the gel
from stores due to our status as non-licensed stunt performers, we attempted to contact the
theatre department; they said that there was no way that we would be able to get our hands on the
gel unless we went to the source. Professor Datta spoke directly with Dr. Zeller, who planned to
give us a sample to determine its physical properties, but after a week’s delay, we called again,
and the president of the company was rather rude to Professor Datta. We attempted to get a hold
of the gel thru other means for a time, until one of our group members called Zeller again. They
spoke for an hour, after which Dr. Zeller had to speak at the UN. Dr. Zeller was too busy to be
able to spend much more time, but he profusely apologized with respect to Professor Datta’s
treatment, and offered as much information as he had with respect to the gel’s properties.
Unfortunately, the gel has never been tested for thermal conductivity and specific heat values,
and he was also unsure of the density. The closest thing to a handbook on the gel is a book he
wrote for stunt performers on how to keep themselves safe while being lit on fire. Further, he
was unable to give us samples because he was entirely sold out for the next few weeks due to the
start of movie season as well as a large order placed by the Department of Defense. He wished
all of us luck on our project, and hopes to be helpful at some point in the future.

Mesh Issues:

   We encountered a number of difficulties while attempting to generate the 3D mesh for our
project. One of the main problems was the fact that it was not easy to close the volumes for our
arm, fabric, and gel cylinders. This was due to jagged ends that were produced during the
scanning of the forearm. A program called Magic was used to smooth out the rough edges on
both ends of the forearm. Next, during the actual mesh generation process in FIDAP, we had to
split up each volume into sub-volumes in order for the meshing to work. In the end however, in
spite of all the difficulties and setbacks, we were finally able to create a mesh that had half a
million elements. In light of the difficulties associated with the mesh generation, performing
sensitivity analysis based on mesh number was not worth the trouble. Instead, we performed
sensitivity analysis and solution convergence based on many other factors. For running the
program using the 3D model, we used one second time steps for a ten-second time duration in
total. The solution converges after one time step and we suspect that the problem is caused by
our mesh issues.
                                                  Stunt Safety, May 11, 2005                  275


IV. Conclusions and Design Recommendations

        Our study revealed that for this problem situation, the 1D solution is probably sufficient
to safely model the heating of the skin due to fire. Although the immense complexity of the 3D
model is not needed for our problem, we are satisfied simply with obtaining a solution from it.
Using the 3D model from a body scan to perform a heat or mass transfer analysis is a new
concept and most of our time as well as that of the Professor Datta and TAs. Our hope is that a
similar process will be used in the future to solve a more complex problem for which the exact 3-
dimensional body geometry is important.

        Another piece of information that we received from Dr. Zeller is that the gel is applied
directly to the skin. Although this is contrary to other research we have done, it would be an
important variable to take into consideration when modeling this problem. Dr. Zeller also
mentioned that a stunt burn typically last for only about one minute. Since some of our
simulations showed that a burn could theoretically last for a longer time, this is proof that a
simulation cannot always be trusted. There is no substitute for actual tests, and the simulation
should be used only as a guide towards the final design. Of course, in terms of burning and stunt
safety, Zel Jel is the first choice of Hollywood movies because other products do not compare in
performance. Any product such as this that might come to the market and claim to be able to
protect a person for 5 minutes or more should be very carefully investigated, because such
performance was only seen in our simulations unreasonable low thermal conductivities.
                                                          Stunt Safety, May 11, 2005                    276


     V. Appendices

     Appendix A

     Governing Equation

     T    T   k  2T
        u             Q
     t    x c p x 2

     Our problem situation does not require a source or convection term. We assume all masses are
     constant (skin, fabric, and gel), that the fabric is flush against the skin, and that the gel uniformly
   covers the fabric. Therefore, our governing equation simplifies to the following:

     Simplified Governing Equation

     T   k  2T
        
     t c p x 2

     Initial Conditions

     Tskin  37 o C  We assume the temperature of the skin to be body core temperature.
     Tgel  5o C  We assume the gel is cooled before application.
     T fabric  25o C  We assume the fabric is at approximately room temperature.

     Boundary Conditions

     T fire  704o C
     Flux = 0 at elbow (at all sides and back of skin for 1D analysis)

     Please refer to Section II for Schematics
                                                   Stunt Safety, May 11, 2005                  277


Input Parameters

TABLE 1: Property values for 1-Dimensional Analysis

                                          THERMAL CONDUCTIVITY                  SPECIFIC HEAT
                 DENSITY (kg/m3)
                                                (W/m-K)                            (J/kg-K)
   SKIN                 1085                            0.288                         1200
  NOMEX
                        1380                            0.13                          3680
  FABRIC
   GEL                  1500                            0.13                          3680

      Skin Properties taken from BEE 453 Website (Datta, A.K.)

      Nomex Fabric Properties [1]

      We were unable to obtain any Zel Jel stunt gel from Dr. Zeller [4]. For our calculations,
       we assumed that it is fairly dense (which may not actually be true) and have assumed it to
       have the same thermal conductivity as the fabric (which we already know is heat
       resistant). In the sensitivity analysis, we explored the effect of lowering the thermal
       conductivity of the gel. We have set the specific heat to be equal to the skin, which is
       also not true in reality, but we wanted to at least provide a value on the correct magnitude
       so the solution would be reasonable and reveal the general shape and trend of the true
       solution.
                                                 Stunt Safety, May 11, 2005                 278


Appendix B

1-D:

PROBLEM STATEMENT:
PROB (2-D, ENER, NOMO, TRAN, LINE, FIXE, NEWT, INCO)
This 1-D problem is modeled with 2-D geometry. It is modeled as a transient process with
energy transfer and no momentum. There is no convection or fluid flow in the process. The
surfaces are assumed to be fixed and the fluid is modeled as incompressible.

SOLUTION STATEMENT:
SOLU (S.S. = 50, VELC = 0.100000000000E-02, RESC = 0.100000000000E-01,
     SCHA = 0.000000000000E+00, ACCF = 0.000000000000E+00)
We used a numerical method called “Successive Substitution” for a maximum of 50 iterations
per time step. No relaxation method factor is used.

TIMEINTEGRATION STATEMENT:
TIME (BACK, VARI = 0.100000000000E-02, TSTA = 0.000000000000E+00, TEND = 300.0,
     DT = 0.1, NSTE = 5000, NOFI = 300, DTMA = 1.0, INCM = 1.1)
We used “Backward Euler” time integration method for this problem. We simulated this process
for 300 seconds with a time step of 0.1 second. The maximum number of steps is set to be 5000
steps and the maximum increment factor between any two adjacent steps is 1.1.


3-D:

PROBLEM STATEMENT:
PROB (3-D, ENER, NOMO, TRAN, NONL, FIXE, NEWT, INCO)
This 3-D problem is modeled with 3-D geometry. It is modeled as a transient process with
energy transfer and no momentum. There is no convection or fluid flow in the process. The
surfaces are assumed to be fixed and the fluid is modeled as incompressible.

SOLUTION STATEMENT:
SOLU (SEGR = 50, VELC = 0.100000000000E-02, SCHA = 0.000000000000E+00,
     CR = 2000, CGS = 2000, NCGC = 0.100000000000E-09, SCGC = 0.100000000000E-09)
We used a numerical method called “Segregation” for a maximum of 50 iterations per time step.

TIMEINTEGRATION STATEMENT:
TIME (BACK, FIXE, TSTA = 0.000000000000E+00, TEND = 100.0, DT = 1.0,
     NSTE = 100)
We used “Backward Euler” time integration method for this problem. We simulated this process
for 100 seconds with a time step of 1 second. The maximum number of steps is set to be 100
steps. Fixed size steps are used for this process.
                                      Stunt Safety, May 11, 2005   279


Mesh Plots




                  FIGURE 11: Mesh Refinement Visuals
                 Top Left: 110 nodes, Top Right: 270 nodes
             Bottom Left: 861 nodes, Bottom Right: 1281 nodes
                                            Stunt Safety, May 11, 2005        280


Temperature vs. Time Plots




           FIGURE 12: Skin Surface Temperature Plots for Various Mesh Sizes
                 (All graphs have been altered to show approximately
                the same temperature scale for comparative purposes)
                      Top Left: 110 nodes, Top Right: 270 nodes
                  Bottom Left: 861 nodes, Bottom Right: 1281 nodes
                                                  Stunt Safety, May 11, 2005       281


1-D FIINP File
/
/ INPUT FILE CREATED ON 16 Mar 05 AT 21:07:07
/
/
/ *** FICONV Conversion Commands ***
/ *** Remove / to uncomment as needed
/
/ FICONV(NEUTRAL,NORESULTS,INPUT)
/ INPUT(FILE= "1dsim.FDNEUT")
/ END
/ *** of FICONV Conversion Commands
/
TITLE

/
/ *** FIPREP Commands ***
/
FIPREP
 PROB (2-D, ENER, NOMO, TRAN, LINE, FIXE, NEWT, INCO)
 PRES (MIXE = 0.100000000000E-08, DISC)
 EXEC (NEWJ)
 SOLU (S.S. = 50, VELC = 0.100000000000E-02, RESC = 0.100000000000E-01,
       SCHA = 0.000000000000E+00, ACCF = 0.000000000000E+00)
 TIME (BACK, VARI = 0.100000000000E-02, TSTA = 0.000000000000E+00, TEND = 300.0,
       DT = 0.1, NSTE = 5000, NOFI = 300, DTMA = 1.0, INCM = 1.1)
 OPTI (SIDE)
 DATA (CONT)
 PRIN (NONE)
 POST (RESU)
 SCAL (VALU = 1.0)
 ENTI (NAME = "SKIN", SOLI, PROP = "mat2")
 ENTI (NAME = "FABRIC", SOLI, PROP = "mat1")
 ENTI (NAME = "GEL", SOLI, PROP = "mat3")
 ENTI (NAME = "BOTTOM", PLOT)
 ENTI (NAME = "LEFTskin", PLOT)
 ENTI (NAME = "RIGHTskin", PLOT)
 ENTI (NAME = "LEFTfabric", PLOT)
 ENTI (NAME = "RIGHTfabric", PLOT)
 ENTI (NAME = "LEFTgel", PLOT)
 ENTI (NAME = "RIGHTgel", PLOT)
 ENTI (NAME = "TOPgel", PLOT)
 ENTI (NAME = "GEL-FABRICinterface", PLOT)
 ENTI (NAME = "FABRIC-SKINinterface", PLOT)
 DENS (SET = "mat2", CONS = 1085.0)
 DENS (SET = "mat1", CONS = 1380.0)
 DENS (SET = "mat3", CONS = 1500.0)
 SPEC (SET = "mat2", CONS = 3680.0)
 SPEC (SET = "mat1", CONS = 1200.0)
 SPEC (SET = "mat3", CONS = 1200.0)
 COND (SET = "mat2", CONS = 0.288)
 COND (SET = "mat1", CONS = 0.13)
 COND (SET = "mat3", CONS = 0.13)
 BCNO (TEMP, CONS = 704.0, ENTI = "TOPgel")
 BCFL (HEAT, CONS = 0.000000000000E+00, ENTI = "BOTTOM")
 BCFL (HEAT, CONS = 0.000000000000E+00, ENTI = "LEFTskin")
 BCFL (HEAT, CONS = 0.000000000000E+00, ENTI = "RIGHTskin")
 BCFL (HEAT, CONS = 0.000000000000E+00, ENTI = "LEFTfabric")
 BCFL (HEAT, CONS = 0.000000000000E+00, ENTI = "RIGHTfabric")
 BCFL (HEAT, CONS = 0.000000000000E+00, ENTI = "LEFTgel")
 BCFL (HEAT, CONS = 0.000000000000E+00, ENTI = "RIGHTgel")
 ICNO (TEMP, CONS = 37.0, ENTI = "SKIN")
 ICNO (TEMP, CONS = 25.0, ENTI = "FABRIC")
 ICNO (TEMP, CONS = 5.0, ENTI = "GEL")
 EXTR (ON, AFTE = 5, EVER = 5, ORDE = 3, NOKE, NOFR)
END
/ *** of FIPREP Commands
CREATE(FIPREP,DELE)
CREATE(FISOLV)
PARAMETER(LIST)
                                       Stunt Safety, May 11, 2005        282


3-D FIINP File
/
/ INPUT FILE CREATED ON 04 May 05 AT 17:04:29
/
/
/ *** FICONV Conversion Commands ***
/ *** Remove / to uncomment as needed
/
/ FICONV(NEUTRAL,NORESULTS,INPUT)
/ INPUT(FILE= "mesh2.FDNEUT")
/ END
/ *** of FICONV Conversion Commands
/
TITLE

/
/ *** FIPREP Commands ***
/
FIPREP
  PROB (3-D, ENER, NOMO, TRAN, NONL, FIXE, NEWT, INCO)
  PRES (MIXE = 0.100000000000E-08, DISC)
  EXEC (NEWJ)
  SOLU (SEGR = 50, VELC = 0.100000000000E-02, SCHA = 0.000000000000E+00,
        CR = 2000, CGS = 2000, NCGC = 0.100000000000E-09,
        SCGC = 0.100000000000E-09)
  TIME (BACK, FIXE, TSTA = 0.000000000000E+00, TEND = 100.0, DT = 1.0,
        NSTE = 100)
  OPTI (SIDE)
  DATA (CONT)
  RELA (HYBR)
    0.3000000000E+00, 0.3000000000E+00, 0.3000000000E+00, 0.5000000000E+00,
    0.3000000000E+00, 0.7500000000E+00, 0.3000000000E+00, 0.3000000000E+00,
    0.3000000000E+00, 0.3000000000E+00, 0.3000000000E+00, 0.3000000000E+00,
    0.3000000000E+00, 0.3000000000E+00, 0.3000000000E+00, 0.3000000000E+00,
    0.3000000000E+00, 0.3000000000E+00, 0.0000000000E+00, 0.0000000000E+00,
    0.0000000000E+00, 0.0000000000E+00, 0.0000000000E+00, 0.0000000000E+00,
    0.0000000000E+00, 0.0000000000E+00, 0.0000000000E+00, 0.0000000000E+00
  PRIN (NONE)
  POST (RESU)
  SCAL (VALU = 1.0)
  ENTI (NAME = "ARM", SOLI, PROP = "mat1")
  ENTI (NAME = "FABRIC_A", SOLI, PROP = "mat2")
  ENTI (NAME = "FABRIC_B", SOLI, PROP = "mat2")
  ENTI (NAME = "GEL_A", SOLI, PROP = "mat3")
  ENTI (NAME = "GEL_B", SOLI, PROP = "mat3")
  ENTI (NAME = "gel_face_A", PLOT)
  ENTI (NAME = "gel_face_B", PLOT)
  ENTI (NAME = "gel_fabric_A", PLOT)
  ENTI (NAME = "gel_fabric_B", PLOT)
  ENTI (NAME = "skin_A", PLOT)
  ENTI (NAME = "skin_B", PLOT)
  ENTI (NAME = "wrist", PLOT)
  ENTI (NAME = "wrist_fabric_A", PLOT)
  ENTI (NAME = "wrist_fabric_B", PLOT)
  ENTI (NAME = "wrist_gel_A", PLOT)
                                        Stunt Safety, May 11, 2005   283

 ENTI (NAME = "wrist_gel_B", PLOT)
 ENTI (NAME = "elbow", PLOT)
 ENTI (NAME = "elbow_fabric_A", PLOT)
 ENTI (NAME = "elbow_fabric_B", PLOT)
 ENTI (NAME = "elbow_gel_A", PLOT)
 ENTI (NAME = "elbow_gel_B", PLOT)
 DENS (SET = "mat1", CONS = 1085.0)
 DENS (SET = "mat2", CONS = 1380.0)
 DENS (SET = "mat3", CONS = 1500.0)
 SPEC (SET = "mat1", CONS = 3680.0)
 SPEC (SET = "mat2", CONS = 1200.0)
 SPEC (SET = "mat3", CONS = 1200.0)
 COND (SET = "mat1", CONS = 0.288)
 COND (SET = "mat2", CONS = 0.13)
 COND (SET = "mat3", CONS = 0.1)
 BCNO (TEMP, CONS = 704.0, ENTI = "gel_face_A")
 BCNO (TEMP, CONS = 704.0, ENTI = "gel_face_B")
 BCFL (HEAT, CONS = 0.000000000000E+00, ENTI = "wrist")
 BCFL (HEAT, CONS = 0.000000000000E+00, ENTI = "wrist_fabric_A")
 BCFL (HEAT, CONS = 0.000000000000E+00, ENTI = "wrist_fabric_B")
 BCFL (HEAT, CONS = 0.000000000000E+00, ENTI = "wrist_gel_A")
 BCFL (HEAT, CONS = 0.000000000000E+00, ENTI = "wrist_gel_B")
 BCFL (HEAT, CONS = 0.000000000000E+00, ENTI = "elbow")
 BCFL (HEAT, CONS = 0.000000000000E+00, ENTI = "elbow_fabric_A")
 BCFL (HEAT, CONS = 0.000000000000E+00, ENTI = "elbow_fabric_B")
 BCFL (HEAT, CONS = 0.000000000000E+00, ENTI = "elbow_gel_A")
 BCFL (HEAT, CONS = 0.000000000000E+00, ENTI = "elbow_gel_B")
 ICNO (TEMP, CONS = 37.0, ENTI = "ARM")
 ICNO (TEMP, CONS = 25.0, ENTI = "FABRIC_A")
 ICNO (TEMP, CONS = 25.0, ENTI = "FABRIC_B")
 ICNO (TEMP, CONS = 5.0, ENTI = "GEL_A")
 ICNO (TEMP, CONS = 5.0, ENTI = "GEL_B")
 EXTR (ON, AFTE = 25, EVER = 15, ORDE = 2, NOKE, NOFR)
END
/ *** of FIPREP Commands
CREATE(FIPREP,DELE)
CREATE(FISOLV)
PARAMETER(LIST)
                                    Stunt Safety, May 11, 2005   284


Appendix C




               Figure 13: 3D meshes shown in FIDAP




             Figure 14: 3D solution magnified (line plot)
                                                    Stunt Safety, May 11, 2005                  285


Appendix D

References

[1] Azom.com. “Polyaramid Polymetaphenylene Isophthalamide ( Nomex ) – Properties and
Applications - Supplier Data by Goodfellow.” 2004.
http://www.azom.com/details.asp?ArticleID=1994.

[2] Datta, A.K. 2004. Computer-Aided Engineering: Applications to Biomedical Processes.
Dept. of Biological and Environmental Engineering, Cornell University, Ithaca, New York.

[3] Datta, A.K. Computer-Aided Engineering: Applications to Biomedical Processes. “Thermal
Properties Appendix.” Course Website. Dept. of Biological and Environmental Engineering,
Cornell University, Ithaca, New York. http://instruct1.cit.cornell.edu/courses/bee453/.

[4] Zeller International. http://www.zeller-int.com/. 2003.

Acknowledgments

Professor Datta for the time he put in to try to obtain a sample of the gel from Zeller
International and for his guidance throughout the course of this study.

Amit Halder and Vineet Rakesh for the time and effort they put in to help us convert the file
from the 3D scan and create a mesh.

Fluent Technologies Support Staff for their help with obtaining a working 3D mesh.

Dr. Gary Zeller for the wonderful information about his gel that he provided us and for his
efforts to send us a sample of his gel.

								
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