(SEM V) THEORY EXAMINATION 2017-18 STRUCTURAL ANALYSIS-II

Structural Analysis – II (NCE-504)

Section-Wise Important Questions & Study Notes

SECTION–A

(Attempt all questions | 2 × 10 = 20)
This section checks definitions, concepts, and theory basics.
Write 2–3 lines only, no derivations.

Carry Over Moment
The moment induced at the far end of a member when a moment is applied at the near end, with the far end fixed.

Castigliano’s Second Theorem
The partial derivative of strain energy with respect to an applied force gives the displacement in the direction of that force.

Why Two-Hinged Arch Is Indeterminate
Because it has one redundant reaction (horizontal thrust), making it statically indeterminate to degree one.

Horizontal Thrust Using Castigliano’s Theorem
Horizontal thrust is obtained by differentiating strain energy with respect to horizontal reaction and equating displacement to zero.

Range of Central Dip
The central dip of a suspension cable lies between 1/10 to 1/12 of the span for economical design.

Effect of Temperature Change in Cable
Increase in temperature increases sag and reduces tension; decrease in temperature reduces sag and increases tension.

Stiffness Coefficient
Force required to produce unit displacement at a degree of freedom while all other displacements are restrained.

Objectives of Structural Analysis
To determine reactions, internal forces, moments, deflections, and assess safety and serviceability.

Plastic Modulus vs Section Modulus
Section modulus is elastic; plastic modulus is based on fully plastic stress distribution.

Plastic Hinge
A section where plastic moment capacity is reached and rotation occurs without increase in moment.

SECTION–B

(Attempt any THREE | 10 × 3 = 30)
Numericals + diagrams are compulsory.

1. Continuous Beam – Slope Deflection Method

Find support moments                        Write slope-deflection equations

Apply boundary conditions                 Draw BMD

2. Influence Line Diagram (Müller-Breslau Principle)

State the principle                               Draw deflected shape

Construct influence line for moment at mid-span

3. Cable Analysis with Pier

Given:                                                  Span, dip, UDL

Find horizontal tension                       Maximum cable tension

Forces on pier                                     Maximum bending moment in pier

4. Continuous Beam with Support Settlement (Flexibility Method)

Choose redundants                            Write compatibility equations

Form flexibility matrix                         Calculate reactions and moments

5. Limit State Design – Required Section Modulus

Use load factor & shape factor          Compute design moment

Find plastic section modulus

SECTION–C

(Attempt any ONE | 10 × 1 = 10)

3(a) Continuous Beam – Moment Distribution Method

Distribution factors                           Carry over factors

Moment balancing                            Final support moments and BMD

OR

3(b) Method of Consistent Deformation

Primary structure                              Compatibility equations

Redundant forces                             BMD