Bolt bench test using a loadcell.
Determine torque-tension relationship by test.
Tapped bolted joint bench test.
Strain gauged bolts for on-site testing.
Installation under a railway vehicle.
Harmonic anlysis of test results
Bolt thermal analysis
Random vibration analysis
Junkers vibration test.
Bolt load analysis
Automaton hold down bolts
Possibly the most devastating engineering failure of 2009 occurred near Sayanogorsk in south central Russia. The photo below shows Russian Prime Minister Vladimir Putin visiting the accident site and is well documented on YouTube and the Boston Globe. A catastrophic accident took place in the turbine and transformer rooms of the hydroelectric plant of the Sayano-Shushenskaya dam causing a transformer explosion and extensive damage to all ten turbines. 74 workers are known to have lost their lives in the accident. The root cause of the incident is the failure of that most basic of engineering components, the 'simple' bolt.
Every engineer experiences some difficulties with bolts at some point in his career. So what typically goes wrong and what can we do to prevent bolt problems? Follow our bolt failure checklist and find calculations to help you.
Bolt Investigation Techniques
The ‘simple bolted joint’ can be anything but simple. MoreVision and BoltScience offer a unique skill set to solve your bolting problems. Please contact John Doyle if you require our assistance with your own bolt problems.
Our Consultancy Services
– Email all the joint details (bolt specification, clamped materials, tightening procedure, applied axial and shear forces, temperature) and using our databases and analysis tools we’ll produce a report which identifies any area of risk. Maybe you would just like an independent review of your bolting procedures?
Bolt Loading Assessment
– Not entirely sure what loads your joint will be subjected to? If classical calculations are not enough we use finite element analysis to calculate the loads to which a bolt is subjected. Analysis methods available to us are inertia load assessment, dynamic load assessment, random vibration assessment, thermal assessment and fatigue assessment.
Bolt Lab Test
– Send us your bolt and in addition to the bolted joint design check report we’ll measure the torque tension relationship for your joint using load cells.
Bolt Value Engineering
– We help clients replace expensive custom made bolts with cheaper alternatives with no loss in structural performance. Our last value engineering exercise save one of our clients over 1 million dollars.
On Site Bolt Testing
– If your joint is too big to send to us we’ll come to you. It may be appropriate to use pre-calibrated strain gauged bolts which we can specially prepare for you. Our last test involved monitoring bolts on a railway vehicle. Our measurements were linked to Google Earth via a GPS to that we could identify parts of the railway infrastructure which gave rise to high bolt loads.
Bolt Failure Investigations
– Ask our team for an independent failure investigation. Our combined bolting experience and analysis tools and skills places you in the strongest position to investigate the root cause of bolt failure. Given the nature of bolt failures this service is offered on an independent and confidential basis.
This is a pretty simple bolt calculation from first principles. For a given bolt size it looks up the characteristics of a bolt from a 'Bolt Lookup Table'. A bolt preload (or clamping load) is...
Bolt spacing and edge distances.xls
"BOLTGRP.xls" is a MS-Excel spreadsheet workbook for analyzing bolt groups...
Power screw calculations V0001.xls
Helix Length and Lead Angle.xls
Bolt torque/tension calc
Screwjack effects of wear on thread stripping load