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Focus
on Fatigue |
MoreVision has developed a number of programs to post-process finite element
results, calculate fatigue damage and to plot damage directly onto the FE
mesh. The assessments cover code of practices used in many countries (UK -
BS7608, France -UIC 515-4 Goodman Diagram, German DIN 15 018, Swedish Volvo
standards) |
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Experimental Methods |
MoreVision strain gauge testing compliments its analysis services. |
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Software
Success |
MoreVision has sold
its innovative
engineering calculation software Research Engineers Inc. for worldwide distribution. The product has already earned MoreVision a
DTI SMART award for innovation. |
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| Composite
Analysis |
MoreVision
has extensive experience in the modelling composite materials. |
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Dynamic
Analysis |
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Avoid resonance by performing a dynamic analysis. |
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Plastic
Analysis |
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What
happens when stress rises above yield? - it may not be as
severe a situation as you think. |
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  Fatigue and Fracture |
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MoreVision have a
Particular Expertise in This Field
 If a component is
subject to repeated applications of structural loading then it will be
susceptible to fatigue failure. Stresses act on small flaws inherent
in the material causing then to grow until they break. Two approaches
can be employed to assess this situation:
• Fatigue Life Assessment.
• Fracture Mechanics Approach.
Using stress information derived from an ANSYS structural analysis
MoreVision have developed custom programs to assess fatigue life or to
study crack growth.
Our library of programs includes methods of assessment used in various
countries following a number of codes:
Fatigue Life Assessment
• UK - BS7608 (fabricated steel), BS8118 (aluminium), BS5400
(bridges), BS2573 (cranes).
• France - UIC 515-4 Goodman Diagram (railway).
• German DIN 15 018 (cranes).
• Swedish Volvo standards (automotive, construction
equipment).
Fracture Mechanics Approach
• UK - PD6493 (fracture). |
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Fatigue of Welded Structures |
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The fatigue life
of a welded structure it totally dependant upon the choice of welded
detail. In the following examples the detail on the left hand side
of the page is improved by adopting the detail on the right hand side.
Just three examples are given though there are generally many ways of
optimising a fabricated structure.
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1) Weld reinforcement and weld toe re- profiling
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The fatigue life of this butt weld is improved by grinding the weld
reinforcement flush with the parent plate. This reduces the stress
concentration at the weld toe. Paradoxically it could be further
enhanced if the weld toes are dressed back 1 to 2mm below the
thickness of the parent plate! The benefit from the removal of poor
quality material at weld toes which contains fatigue prone inherent
flaws outweighs the slight increase in stress due to loss of net
section.
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2) Removal of weld stop starts  |
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The
presence of stop start defects in a weld will reduce the fatigue life
of a weld.
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3) Do not weld on plate edges  |
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Welds
on the edge of a stressed plate have a lower fatigue life than welds
which stop 10mm short of the edge. |
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Top
Software Tools |
MoreVision
have some 20 years experience of problem solving with ANSYS®. They
have developed a library of macros and software tools customizing
ANSYS for specific problems. |
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Bolted Joint Analysis |
 MoreVision uses 'Boltcalc' software
in conjunction with FEA for fast & accurate assessments. |
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Partnering
Client Design Teams |
 Will it fall off? Is it strong
enough? How long will it last? These are the questions on the minds of many
designers. MoreVision can team up to perform simple strength assessments to
allow designers to move forward with the confidence that their designs will
ultimately satisfy structural criteria. |
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Independent
Design Audits |
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A
fresh pair of eyes can offer an new insight into design critical
problems. |
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Fixed
Price Contracts |
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Whenever
possible MoreVision offers fixed price contracts from the outset of a
project. |
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Failure
Investigations |
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Simply strengthening an area
may not give you the results you want and could make the problem worse.
Before a solution can even be considered it is imperative that the mechanics
of the failure are completely understood. |
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Can
we live with cracks? |
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Let MoreVision help you decide using their custom PD6493 software. |
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Too
Hot to Handle? |
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MoreVision
helps clients solve temperature problems. |
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Stress
Overload? |
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Use
MoreVision to offload work when you're too busy to cope. |
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