Week 1: Structures

In addition to the exercises below, much of the Harding handout is available in text format as are the study notes for Chapter 1 of Understanding Buildings .

Exercises on Structures

Due Tuesday, January 18 // help sessions: Monday, Jan. 10, 2 pm in 4300 and Monday, Jan. 17, 2 pm in 4300

1) make the cardboard and white glue beam model as described on the last page of the calculation handout (Harding notes)

2) determine a beam size for the same structure as in the Harding notes, except that that right-hand support is all the way at the end of the beam (no cantilever), and an additional 200 lb load occurs at the original support location (one more joist load, which previously was absorbed directly by the support.

3) how do the two beams compare in dimensions and weight? (weight information is on the "Properties" chart)

4) Looking at the "Properties" chart, would it be true to say that the section modulus of structural lumber is proportion to the width of the member, other things being equal?

5) Two model exercises:

(a) Buckling and slenderness: select a slender linear element (strip of wood, plastic, or metal) and find its total compression resistance for various increments of length. Start with a ratio of length to thickness of at least 200 for the longest specimen

(b) one-way vs two-way spanning: test a thin planar element in bending (a sheet of cardboard, glass, plastic, metal) with a single load at the center of the span. Test specimens with the following shapes and support conditions at the edges:

(a) square sheet, two opposite edges supported;

(b) square sheet, three edges supported;

(c) square sheet, four edges supported;

(d) rectangular sheet with the small dimension the same as in (c) and the long dimension a multiple of the short of increasing magnitude in successive specimens: 1.25. 1.5, 1.75, 2.0, and so on.

Present results as tables or diagrams, with clear explanation of procedures, and comments on patterns observed (sustainable load, modes of failure, etc.)