Virtual Work / Unit-load: Truss deflections - Example 1

Worked example of the calculation of the deflections of a truss using virtual work / unit-load method.

[@gotemnausiah6495]

Thank you for this video, just wanted to ask whether the horizontal unit load applied is always to the right or could it be applied either side?

[@ProgrammedMechanics]

You can assume any direction, a positive final answer will confirm your assumption.

[@TheSterlingArcher16]

Good detail of the process. Very unintuitive however that summing the axial displacements would result in a total deflection in the direction specified.

[@ProgrammedMechanics]

there are 2 prior videos in the playlist to help with the concept - kzbin.info/aero/PLG7h9Zm4rTYxo36g3Rl6C7_8gLBUGKv16

[@kashifanihaan4032]

Isn't this a determinate truss? How do we approach a problem with indeterminate truss??

[@ProgrammedMechanics]

yes the truss in this example is determinate, for indeterminate see kzbin.info/www/bejne/oWfbiItpa8qFmdk

[@Mohamed-ef5zw]

How can I check if this deflection is acceptable or not?

[@ProgrammedMechanics]

deflection (serviceability) limits will be set in design codes / standards

[@Mohamed-ef5zw]

@@ProgrammedMechanics What is the deflection limits for trusses in Euro code? I couldn’t find it.

[@sohailahmed5039]

Sir you have stopped making videos. There is almost 95% work left undone by you both in structure analysis I and II. Any reasone for not making any video.

[@ProgrammedMechanics]

Never say never, but I only record videos for topics that I teach. For each topic there is only a limited number of examples as I follow up with many hours of on-campus problem solving workshops.

[@sohailahmed5039]

@@ProgrammedMechanics i completely agree sir and i knew it might be the answer too. But do you really teach these few topics, as structure analysis surely does not contain only these topics....anyways your explaination really helps

[@ProgrammedMechanics]

@sohailahmed5039 the team of us teach a full stream from statics -> strength of materials -> structural mechanics -> computer methods -> structural dynamics -> finite element theory (and practice). We have reduced the number of hand calculation methods we teach, as they are never(/ very rarely) used in practice, but we do make sure that students are comfortable with both the theory of underlying computer packages they will use and the safe practice of these packages.