Integrated judgement — exercises | Queensferry

Module 18Level 4reactions and load path

Reading an overhang in full

A load sits on the overhang of a beam beyond its far support. Which single statement reads the whole response correctly?

Predict first, then reveal

Reason from the supports, the movement and equilibrium — not from what looks familiar.

AThe back span hogs, the far (near) support pushes up hard while the other reaction reverses to a hold-down, and the moment is zero at the pin and at the free tip.BThe beam sags between the supports and both reactions push up, as for a normal simple span.CThe moment is largest at the free tip, where the load is.

Module 18Level 5change and sensitivity

One loaded span, several consequences

In a three-span continuous beam, only the middle span is loaded. Which reading joins the consequences correctly?

Predict first, then reveal

Reason from the supports, the movement and equilibrium — not from what looks familiar.

AContinuity hogs the beam over the interior supports and lifts the unloaded end spans, so the end reactions reverse downward — and unanchored end bearings can lift off.BOnly the middle span responds; the end spans do nothing.CAll three spans sag downward together.

Module 18Level 4deflected shape

A portal under symmetric gravity

A symmetric portal frame carries a symmetric gravity load on its beam. Which combined statement is right?

Predict first, then reveal

Reason from the supports, the movement and equilibrium — not from what looks familiar.

AIt does not sway (symmetry), but the columns still bend, because the rigid joints transfer the beam's end moments into them.BIt sways to one side and the columns carry only axial force.CThe columns stay straight because only the beam is loaded.

Module 18Level 4stable or mechanism

How close to a mechanism?

An all-pinned rectangular portal is currently a sway mechanism. Judging its sensitivity, what is the smallest change that would make it stable?

Predict first, then reveal

Reason from the supports, the movement and equilibrium — not from what looks familiar.

AAny one of: make a single joint rigid, fix one base, or add one diagonal brace — each alone removes the sway mechanism.BNothing short of rebuilding it entirely will help.CAdding more pinned members, to increase the count.

Module 18Level 3software check

Why qualitative judgement matters

With powerful analysis software available, why is the qualitative judgement taught in this course still essential?

Predict first, then reveal

Reason from the supports, the movement and equilibrium — not from what looks familiar.

ABecause software gives magnitudes but not validation — only a prediction of the behaviour lets you tell whether a converged result describes the structure you meant.BIt is not — modern software makes hand judgement obsolete.COnly so you can do the sums faster by hand.