UWE Bristol Engineering showcase 2015

Nick Macey
Mechanical engineering
Project supervisor
John Kamalu
Increasing the durability of resin based handholds
used on artificial climbing walls
Current climbing holds are mainly
constructed out of a polyurethane resin,
which is fairly durable, but tends to
become increasingly brittle with age
which can lead to chipping or cracking.
Lack of ductility will lead to sudden failure
especially when being fastened to uneven
surfaces. Larger holds are often hollowed
out to reduce their weight, though this
can lead to reduced tensile and
compressive strength, increasing
instances of failure.
Establishing failure parameters
Poor handling:. Dropping of holds and
loose storage can cause fractures It can
also result in chipping; sharp edges left on
chipped handholds can be dangerous as
potential harm to the climbers is a high
possibility.
Over tightening holds when reattaching
holds to the wall. This can cause an
internal fracture, which can cause failure
during use
Surface smoothing, brand new climbing
holds have a surface finish similar to
sandpaper, prolonged use of handholds
will result in the multitudes of hands and
shoes wearing away the high friction
surface, leaving behind a smooth and
slippery handhold
Testing Samples
Samples of polyurethane were tested to destruction
Stress vs 20strain of all 4 Samples
Stress (Mpa)
15
10
Sample 1
5
Sample 2
0
Sample 3
-0.002 0 0.002 0.004 0.006 Sample 0.0084
-5
Strain
Prototype handholds were created and simulations
Project Summery
The aim of this project is to investigate
the properties of current climbing
handholds and attempt to select a
material and design that would create
climbing holds with a longer life span
without increasing the overall cost.
Objectives
1. To carry out an in-depth investigation
of the problems currently associated with
artificial climbing handholds.
2. Carry out laboratory work to compare
the strength and wear properties of
current products and also establish failure
parameters.
3. Carry out computer simulation and
prototype testing
Conclusion
Damage from climbing aids, mainly ice
axes. Ice axes are highly destructive
towards handholds causing chipping,
scratches and sharp edges. Due to the
short lifespan of holds used in this nature,
Ice axe training is usually carries out on
holds that have been retired
Polyethylene Terephthalate (unfilled,
semi-crystalline) is a viable replacement
material for polyurethane, as it meets all
the mechanical parameters set out in CES,
is almost 3 times cheaper and due to its
relatively low melting point compared to
polyurethane, which does not have a
liquid phase, Handholds can be recycled
and recast.