44. Recording inter-nodal loading

Direct Stiffness Method - Beam and Frame Analysis
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Questions and discussion for this lecture live here. Fire away by hitting Reply below :fire:

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Hi Dr Sean

  • I am wondering why we use simple formula ‘wl^2/12’ to calculate ‘Moment’ for inter-nodal loading. We solved stiffness matrix equations to calculate ‘Moment’ at primary nodes.
  • Locking the memeber with fixed-ends for inter-nodal loading is kind of standard procedure?

Thanks
Yan

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We use this formula because we’re calculating the fixed-end moment that the inter-nodal loading will apply at each end of the loaded element. The stiffness method can only accommodate loading at a nodal point - so this is required when we have loading between nodes that we want to consider - otherwise the influence of this loading would not be captured.

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Hey Sean, Very informative videos thanks for all your efforts in creating this content.

I was wondering what would the equivilant nodal forces look like for a UDL over a beam with one or both ends pinned?

Thanks.

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Hey @Derek_Bailey

Naturally it will depend on the applied loading. You’ll be able to pull the required formulae out of any standard structures text, for example, this is a good one I’ve used for years…

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Hope that helps,
Seán