FE Civil Practice Question Solution included after investigation
CASE E-045 · FE

The Beam Moment That Peaked at 75 kip-ft, Not 300

The total load was 30 kips. Multiplying by half the span produced the wrong bending moment.

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Case E-045 engineering failure visual
HOW THIS WORKS

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Follow the investigation process used in the field — in five guided steps.

1

Inspect

Review the problem, diagram, and evidence.

2

Commit

Choose your hypothesis.

3

Prove

Run calculations and test your idea.

4

Fix

Select and validate a safe correction.

5

Sign Off

See the full debrief and key takeaways.

Case Brief

SAME PRINCIPLES. HIGHER STANDARDS.
PROBLEM STATEMENT

A 20 ft simply supported beam carries a uniform load of 1.5 kip/ft over the entire span. A design note multiplies the total 30 kip load by 10 ft and reports 300 kip-ft maximum moment. Determine the correct maximum bending moment and identify what the 300 kip-ft calculation omitted.

Structural Engineering Civil Design Verification Root Cause Analysis Safe Correction
E-045
INVESTIGATION WORKSPACE WORK THROUGH THE CASE — YOUR CHOICES MATTER.
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CASE CLOSED · ENGINEERING VERDICT

What actually failed — and what should change.

What failed

The external load moment about one support was mistaken for internal maximum bending moment.

What was missed

Support reactions and section equilibrium.

Corrected model

For a simple beam under full-span UDL, Mmax=wL²/8.

QUICK ANSWER

For a simply supported beam carrying a uniform load over the full span, Mmax=wL²/8. With w=1.5 kip/ft and L=20 ft, Mmax=1.5×20²/8=75 kip-ft at midspan.

ENGINEERING TAKEAWAY

For a simply supported beam with uniform load over the full span, Mmax=wL²/8 at midspan.

CASE QUESTIONS

Questions this case should settle.

What is the maximum moment formula for a simply supported beam with full-span UDL?

Mmax=wL²/8.

Where does maximum moment occur for symmetric full-span UDL?

At midspan, where shear is zero.

NEXT FE PRACTICE QUESTION

The Column That Buckled Near 497 kips

Structural Engineering · 5–10 min

Continue Practice →
WHAT YOU’LL LEARN

Real failures. Lasting skills.

Each case is designed to build the judgment, analysis, and confidence you need for engineering exams — and beyond.

  • Apply core engineering concepts to real-world problems
  • Practice structured troubleshooting and analysis
  • Strengthen exam-ready thinking through realistic scenarios
COMMON QUESTIONS
Do I need prior knowledge to use these cases?

Basic subject familiarity helps, but every case is designed to teach through the investigation itself.

How long does a case take?

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Are the cases aligned with engineering exams?

Each case is mapped to a verified exam, subject, topic, and misconception before publication.

What happens after I complete a case?

The sealed debrief unlocks with the root cause, corrected reasoning, fix, and takeaway.