Case Study
Innovative
cable tie design
Millepede Cable Ties
made use of FEA's Engineering Consultancy
Services department to help optimise the design of a patented new type of cable tie. By
using LUSAS Analyst a series of nonlinear contact analyses were done to investigate
the deformation of a typical cell in the cable tie. This resulted in an improved tie
design which gave easier threading of the tie through itself and an increased latching
load to be achieved.
| The 8mm-wide
cable ties are made from nylon-66 polyamide and are of a self-locking chain-link type of
design. Each tie consists of a number of 5mm long cells which have a neck region, arms, a
hinge and securing latch - all of varying cross-sectional shapes and dimensions. In use, a
tie is wrapped around cables to be bound together and threaded through itself to tension
and secure the connection. Each tie is designed to withstand tensile forces of 200N. They
are intended to be used wherever conventional cable ties are used but have the important
advantage of zero-wastage due to their self-locking system. |
|
Dimensional data was provided in DXF format initially but subsequently
modifed in LUSAS Graphics as minor amendments and optimisation of the tie dimensions
occurred. Two slightly different tie designs were analysed - the main difference being the
inclusion of a small extension of the latch into the corner of the hinge to act as a
stiffening device when the tie deforms. Due to symmetry only a quarter model of each tie
cell had to be analysed. Uniaxial stress-strain data provided parameters for the LUSAS
hyperelastic nonlinear material model. The LUSAS Ogden rubber material model was chosen
because it allowed fine tuning of parameters to closely match the stress/strain curve
required. A full 3D nonlinear contact analysis was performed with slidelines modelling
surfaces of the cell that came into contact during deformation.
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Contour
plots of maximum principal stretch and more importantly load/displacement graphs were
obtained for each modification to the original cell designs. Andy Harsley, Technical
Director at MCT Ltd said: "The results produced from LUSAS Analyst made it
possible for us to optimise the shape and dimensions of the cable tie cells to give the
performance we required for the specified loading conditions."
Private investment to further develop the cable ties
was found in
the USA and Australia, where a licensing deal was concluded.
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"The results produced from LUSAS
Analyst made it
possible for us to optimise the shape and dimensions of the cable tie cells to give the
performance we required for the specified loading conditions."
Andy Harsley, Technical
Director, Millepede Cable Ties
Other LUSAS Analyst case
studies:
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Software Information
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