NEWS
Motovated Design & Analysis Newsletter - November 2006
Hello again,
We hope you're all making the best of the fine
weather. We've updated our website, please check it out!
In this issue we provide you our answers to the
problems given in the previous newsletter. We hope you find these helpful in
understanding some of the limitations and assumptions made when building an FEA
model, and some hidden pitfalls, especially when using free, CAD embedded
versions!
We also have some updates on the FX Bike project, and
please check below as this month's word problem is quite a crack-up, literally!
Greg
Morehouse
Managing Director
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www.motov8d.co.nz
If you have any comments on the new website please
feel free to email them.
All respondents will be
entitled to a free half-hour consultation on any problem...
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Tips and Tricks: designing sheet metal parts to reduce weight
Sheet metal parts may be shrewdly stiffened using
pressed or formed features, without having to increase plate thickness.
Of particular importance to parts under bending or
buckling loads, this effectively improves the section properties, namely the
second moment of area, and can do wonders for the aesthetic appeal of a part.
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Engineering Word Problem |
A backhoe weighing 8 tons is on top of a flat-bed
truck and heading east on Interstate 70 near Hays, Kansas.
The extended shovel arm is made of hardened steel and the approaching
overpass is made of commercial-grade concrete, reinforced with 1 ½ inch steel
rebar spaced at 6 inch intervals in a crisscross pattern layered at 1 foot
vertical spacing.
Solve: When
the shovel arm hits the overpass, how fast do you have to be going to slice the
bridge in half? (Assume no effect for
headwind and no breaking by the driver...)
Extra credit: Solve for the time and distance
required for the entire rig to come to a complete stop after hitting the
overpass at the speed calculated above.
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>>Click
pictures to enlarge |
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Answer:
For those of you with enough spare time to work it out - congratulations! The
answer is an energy balance: the kinetic energy of the truck is converted into
the work done to break the concrete and steel (and presumably bend the shovel
arm), accompanied by loud crashing sounds. For those of you content to know it
wasn't you who did something that stupid, and not worry about the numbers, our
answer is: pretty fast!
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Article of Interest - FX Adventure Bikes International Release
(www.fxbikes.com) |
For those of you following the FX Adventure
ultra-lightweight motorcycle, you will be pleased to know that the first
production bike was completed and made its debut at the World Mountain Biking
round in Rotorua. Now it's off for show and tell in the States.
All of you interested in investing can contact Mike
Hodgkinson at:
mh@fxbikes.com |
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Thanks again for your continued support.
Please don't hesitate to contact us with any
questions or comments. We are always keen to review any projects or
designs we might be able to help you with.
Our complimentary calendars for 2007 will be coming out soon, please pop
us an email if you don't receive yours by the New Year.
Greg and the team at Motovated,
"Engineering Your Vision"
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