Structural Analysis - Day 1 - Questions

1. A straight beam 150 ft long is installed when the temperature is 40°F. It is support so that only 0.5 in expansion is allowed. Lateral support prevents buckling. If the temperature increases to 100°F – Find the compressive stress in the member.

2. A cantilever beam is 7 ft long. The cross section is 5.5 in wide and 4.5 in deep. E = 1.5x10^6 psi. There are two concentrated: 150 lbf forces 1 ft from the free end and 100 lbf 2 feet from the free end. Find the tip deflection.

3. A steel truss as shown below has R1 pinned and R2 is a roller. The length to Area ratio for each member is 45 in^(-1) E of steel is 29,000 ksi. Find the vertical deflection where the load is applied.

4. A bimetallic spring is constructed of aluminum with a ¼ in by 2 in cross section bonded on top of a 1/8 in by 2 in steel strip. E of aluminum = 10,000 psi, E of steel is 30,000 psi. Find the equivalent all aluminum centroidal area moment of inertia of the cross section.

Structural Analysis - Day 1

Chapter 44 - Strength of Materials - 12 Problems

Structural Steel: Compression and Beam-Columns - Answers

I marked these pages:



K, Effective length factor - Figure 61.2 - Page 61-3



I also marked some of the pages I used in the steel book - because it took so long to find them.

(I tried to condense the answers for the past couple days - but I don't look how they look, so I'm going back to the old way.)

Today's Answers:

Structural Steel: Compression and Beam-Columns - Questions

1. A 22 ft high column pinned at both ends made from an A36 channel and wide flange as shown. Column is constrained in the x plane at mid height.



a) Find the cross sectional area
b) Centroidal moment of inertia about x-axis
c) Centroidal moment of inertia about y-axis
d) Radius of gyration about x- axis
e) Radius of gyration about y- axis
f) Slenderness ratio of column in x-axis
g) Slenderness ratio of column in y-axis
h) Maxmimum slenderness ratio
i) Allowable compressive stress
j) Allowable axial compressive load

2. Select A36 columns of the frame shown. Assume to be braced in plane perpendicular to frame. Girders are W12x106



3. Truss shown is constructed of a variety of members, all of which are assumed to be pin ended. Determine whether all members are adequate, specify replacements with same nominal depth. Assume top chord is braced laterally at every joint.

Top and Bottom Chords W8x24 (A36)
Diagonal bracing L3.5 x 3.5 x 3/8 (pair)
Vertical members L 4 x 4 x 3/8 (pair)


4. A tall column is as shown. The strut is the lateral bracing. No compression flange support. Select an economical A36 W18 section based on stress and deflection.

Structural Steel: Compression and Beam-Columns

Structural Steel: Compression and Beam-Columns

Chapter 61 Structural Steel: Compression members - 5 problems
Chapter 62 Structural Steel: Beam-Columns - 4 problems

Structural Steel: Beams - Answers

I didn't mark any pages for this. I had already marked the pages of the beam diagrams in my steel manual.



Today's answers:

Structural Steel: Beams - Questions

1. A 24 foot steel beam of A36 steel is simply supported on its left end and 7 feet from its right end. A load of 3200 lbf/ft is uniformly distributed over its entire length. Lateral support at reactions only. The beams dead weight is 60 lbf/ft. Choose a W shape. Do not check shear.


2. Select an A36 W shape with lateral support every 6 ft to span 22 ft And carry a uniform load of 1.2 kips/ft Including a 50 lbf/ft dead load. Max deflection is L/240


3. A 60 ft steel beam carries a dead load of 1.5 kip/ft, excluding self weight, over entire span. Supports are at 0 ft (A), 30 ft (C), 55 ft(D) and a hinge is at 25 ft(B).
a) Find the reaction at 0 ft (A)
b) Find the Reaction at 30 ft (C)
c) Find the reaction at 55 ft (D)
d) Find the absolute minimum Shear value
e) Find the location of the maximum shear
f) Find the maximum Moment
g) Find the location of the maximum moment
h) Use unbraced length of 30 ft, find the best W18 section of A36 for moment capacity
i) Find the actual shear stress for the beam chosen
j) Using 42 ksi steel, for the same shape chosen, find the unbraced length that permits the development of 0.66Fy bending stress