PERSONAL-COMPUTER-BASED SOFTWARE PROVIDES ACCURATE UNDERSTANDING OF
CRITICAL ISSUES INVOLVED IN AUTOMOTIVE SEAL DESIGN.

EASi Engineering, Inc. has announced the introduction of a
personal-computer-based software package that can greatly simplify the
process of optimizing the design of air-tight seals. The engineer enters
the geometry and material of the seal and the velocity, mass and geometry
of the closure. The program performs a nonlinear finite element analysis
and provides all the information needed to determine the seal tightness,
durability and closure force of the design. The initial design can be
modified to analyze a new iteration with very little effort. The first
release of the software will be specially designed for automotive seal
applications such as doors, hoods and deck lids. Further releases in the
near future will address other application areas such as aerospace,
appliances, power plants, etc. The program costs $8000 in the single user
version.

The new software package offers the ability to streamline what has been up
to now a difficult and uncertain design task. The major considerations in
automotive seal design are minimizing wind noise while maintaining the
durability of the seal and avoiding the need for excessive closure force.
Generally, harder seal materials reduce wind noise and provide better
durability at the price of increased closure force. Managing this tradeoff
has been difficult up to now because the hand calculations which have been
used do not capture the complexities of the nonlinear materials used as
seals. The only programs capable of handling this type of problem to date
run on mainframes and supercomputers and generally cost several thousand
dollars for each analysis run. Expensive changes are often required at the
prototype stage when physical testing reveals problems with the initial
design. At this point, time and cost considerations generally make it
impossible to even attempt to optimize the design.

EASi-SEAL overcomes these problems by placing all of the tools required to
accurately analyze seals on the desk of any engineering with a personal
computer. The engineer first defines the geometry of the seal and closure
either through the programs own drawing tools, by importing a
computer-aided design file or using a digitizer. Next, comes the input of
material data in the form of a stress-strain curve. Once properties of a
given material have been input, they can be recalled for use at any time.
The engineer also enters the velocity and weight of the closure. Error
checks on both material and geometry are automatically made by the program
such as that the material is hyper-elastic and that the closure impinges
on the seal. Next, the program automatically extrudes the geometry into
solids, meshes the components, applies boundary conditions and material
properties and performs a finite element analysis which takes both the
material and geometric nonlinearities of the problem into account. This
analysis, which runs without user intervention, takes several hours
depending on the complexity of the geometry and type of computer used.

The program output provides all of the information required by the engineer
including animation of seal cross-section, load/deflection curves,
stress/strain contours and force/time curves. The time-stepped animation
of the seal cross-section provides an intuitive understanding of how the
seal is functioning which often aids in improving the design through
subsequent iterations. The force-time graph can be shown on the same
screen with the curve used to control the portion of the animation that is
viewed. The force vs. deflection chart shows the tightness of the seal
with greater deflections indicating tighter sealing and lower durability.
The stress/strain contour chart helps the engineer avoid the situation
where the seal takes a permanent set. All in all, the depth and accuracy
of the analysis goes far beyond hand calculations at a cost which is well
under that associated either with mainframe analysis or physical testing.

Founded in 1981, EASi Engineering has a staff of over 100 professionals and
is one of the largest suppliers of computer-aided engineering services to
the automobile industry. EASi's capabilities include structural crash
simulation, occupant simulation, biomechanics, linear and nonlinear finite
element analysis, optimization, kinematics and dynamic analysis.
Additional capabilities includes analysis of noise, vibration and
harshness, and alternate materials evaluation including structural
plastics and composites. The company also offers EASiBUMPER software which
allows the material and geometry of automotive bumpers to be analyzed and
optimized in the concept phase on a personal computer without building a
prototype.

EASi Engineering Inc
691 N. Squirrel Rd, Ste 11, Auburn Hills, MI 48057
313-377-4200;  fax: 313-377-2342

  +---------------------------------------------------------------+
  |   From the America Online - New Product Information Services  |
  +===============================================================+
  | This information was processed from data provided by the      |
  | above mentioned company. For additional details, contact the  |
  | company at the address or telephone number indicated above.   |
  |    All submissions for this service should be addressed to    |
  |   BAKER ENTERPRISES, 20 Ferro Drive, Sewell, NJ 08080 U.S.A.  |
  +---------------------------------------------------------------+
