Structural Engineering
10–15 of 110 itemsNCEES draws between 10 and 15 of the 110 from this area on any legal paper. Its outline lists 8 sub-topics; the bank holds 56 verified templates against them, which expand to 1,556 questions.
Sub-topics, from the NCEES outline
- AAnalysis of statically determinant beams, columns, trusses, and frames
- BDeflection of statically determinant beams, trusses, and frames
- CColumn analysis (e.g., buckling, boundary conditions)
- DStructural determinacy and stability analysis of beams, trusses, and frames
- EElementary statically indeterminate structures
- FLoads, load combinations, and load paths (e.g., dead, live, lateral, influence lines and moving loads, tributary areas)
- GDesign of steel components (e.g., codes and design philosophies, beams, columns, tension members, connections)
- HDesign of reinforced concrete components (e.g., codes and design philosophies, beams, columns)
5 worked problems
Real questions from the bank, at the depth the exam asks them. Pick an answer first: the reasoning opens when you do, along with why each wrong answer is tempting.
Question 1 of 5
A column 16 ft long has an effective length factor of 1.2 and a governing radius of gyration of 1.5 in. Its slenderness ratio is most nearly:
Column 16 ft long with an effective length factor of 1.2 and a governing radius of gyration of 1.5 in. Show the answer and the reasoning
Why C
Given: L = 16 ft = 192 in, K = 1.2, r = 1.5 in. Relation: KL/r, with KL and r in the same unit so the ratio is dimensionless. Substitute: KL/r = 1.2(192)/1.5 Result: KL/r = 154.
Why A is tempting
Left the length in feet. The radius of gyration is in inches, so both must match.
Why B is tempting
Divided by K instead of multiplying. The effective length is K times the actual length.
Why D is tempting
Multiplied by the radius of gyration instead of dividing.
Source NCEES FE Reference Handbook 10.6 — Civil Engineering, Structural Design
Question 2 of 5
A two-axle vehicle crosses a simply supported span of 28 ft. The leading axle carries 8 kips and the trailing axle 32 kips, spaced 12 ft apart. The maximum reaction at the near support is most nearly:
Two-axle vehicle crossing a simply supported span of 28 ft, the leading axle carrying 8 kips and the trailing axle 32 kips at 12 ft spacing; the reaction peaks when the axles are pushed as far toward one support as the spacing allows. Show the answer and the reasoning
Why C
Given: Span 28 ft; axles 8 and 32 kips, 12 ft apart. Relation: The reaction influence line peaks at the support, so the leading axle sits over it: R = P1 + P2(L - d)/L. Substitute: R = 8 + 32(16)/28 Result: R = 26.3 kips.
Why A is tempting
Ignored the trailing axle entirely.
Why B is tempting
Split the axle loads evenly, which ignores where the vehicle sits.
Why D is tempting
Swapped which axle sits over the support.
Source NCEES FE Reference Handbook 10.6 — Civil Engineering, Structural Design
Question 3 of 5
A singly reinforced beam is 16 in wide with an effective depth of 27 in, As = 2 in^2 of Grade 60 steel and f'c = 4 ksi. Its nominal moment capacity is most nearly:
Singly reinforced concrete beam 16 in wide with an effective depth of 27 in to 2 square inches of tension steel near the bottom face. Show the answer and the reasoning
Why A
Given: b = 16 in, d = 27 in, As = 2 in^2, fy = 60 ksi, f'c = 4 ksi. Relation: a = As fy/(0.85 f'c b); Mn = As fy (d - a/2). Substitute: a = 2.206 in; Mn = 2(60)(27 - 1.103)/12 Result: Mn = 259.0 ft-kips.
Why B is tempting
Used the full effective depth as the moment arm. The compression resultant sits a/2 below the top face.
Why C is tempting
Added half the stress block depth instead of subtracting it.
Why D is tempting
Left the answer in inch-kips.
Source NCEES FE Reference Handbook 10.6 — Civil Engineering, Structural Design
Question 4 of 5
A planar truss has 34 members, 19 joints and 5 reaction components. Its degree of static indeterminacy is most nearly:
Planar truss with 19 joints and 5 reaction components; determinacy compares the member and reaction count against the two equilibrium equations available at each joint. Show the answer and the reasoning
Why D
Given: m = 34 members, r = 5 reactions, j = 19 joints. Relation: Planar truss: degree = m + r - 2j (two equations per joint). Substitute: 34 + 5 - 2(19) Result: 1 (zero means determinate).
Why A is tempting
Used 3j, which applies to rigid frames. A planar truss joint gives two equilibrium equations, not three.
Why B is tempting
Subtracted the reactions. Both members and reactions are unknowns and are counted together.
Why C is tempting
Reversed the sign of the whole expression.
Source NCEES FE Reference Handbook 10.6 — Civil Engineering, Structural Design
Question 5 of 5
A continuous beam runs over two equal spans of 24 ft each and carries a uniform load of 1.5 kip/ft over its full length. The reaction at the interior support is most nearly:
Beam continuous over three supports A, B and C, with two equal spans of 24 ft carrying a uniform load of 1.5 kip per foot over the full length. Show the answer and the reasoning
Why C
Given: Two equal spans L = 24 ft, w = 1.5 kip/ft throughout. Relation: Two equal continuous spans: interior reaction 1.25wL, end reactions 0.375wL. Substitute: R = 1.25(1.5)(24) Result: R = 45.0 kips. Check: 1.25wL + 2(0.375wL) = 2wL = 72.0 kips, the total load.
Why A is tempting
Gave an end reaction rather than the interior one.
Why B is tempting
Assumed each span behaves independently, giving wL/2 from each side. Continuity draws additional load onto the interior support.
Why D is tempting
Assigned the entire load on both spans to the interior support.
Source NCEES FE Reference Handbook 10.6 — Civil Engineering, Structural Design
Four mistakes that cost the question
Each of these lands on an answer that is offered, so it costs the question outright. The minutes are our estimate of the time each one burns on top, against an average of 2.9 minutes a question (320 minutes for 110).
Costs the question and about 3 min
Leaving out the effective length factor, or checking the wrong axis
Slenderness is KL/r and the Euler load is π²EI/(KL)². Dropping K changes the buckling load by up to four times. A column buckles about the axis with the larger KL/r, which is the weak axis only when both axes have the same unbraced length.
Costs the question and about 4 min
Placing a moving load at midspan by habit
For the largest reaction from a set of axles, put the heavier axle over the support with the rest on the span; for the largest shear or moment at a section, the influence line says where. The midspan position gives a value that is offered.
Costs the question and about 2 min
Mixing nominal and design strength
Design strength is the resistance factor φ times the nominal strength: 0.9 for steel flexure and tension yielding, 0.75 for tension rupture, 0.9 for tension-controlled concrete beams. Questions ask for one and offer both, and since they differ by exactly φ the wrong one always looks reasonable.
Costs the question and about 2 min
Miscounting reactions when checking determinacy
A pin supplies two reactions, a roller one and a fixed support three. Counting a pin as one, or a fixed support as two, shifts the degree of indeterminacy by one, and the neighbouring integers are all offered.
Questions about Structural Engineering
Which design codes does Structural Engineering use?
The design sub-topics cover steel and reinforced concrete components: AISC for steel and ACI 318 for concrete, with ASCE 7 load combinations. Steel can be asked in LRFD or ASD, so read which before choosing factors.
Do I need indeterminate analysis?
Only elementary cases: propped cantilevers, fixed-end beams and two-span continuous beams, which are answered from standard formulas for reactions, moments and deflections.
How do I check determinacy quickly?
For a planar truss compare members plus reactions with twice the joints: equal is determinate, more is indeterminate by the difference, fewer is unstable. For beams, count reactions against three equilibrium equations plus one for each internal hinge. A structure that counts as determinate can still be unstable if its reactions are all parallel or all concurrent.
Why is every structural question drawn?
Because the geometry is the question: support types, load positions and member layout. On the official NCEES practice exam every structural item carried a figure, which is why all five problems on this page do too.
How many study hours this area is worth · Using the handbook under the clock