Lecture #3 (FA19).pptx - ART 2223 \u2013 STRUCTURES II LECTURE#3 Lesson Objectives \u2022 Distinguish the types of wood products \u2022 Distinguish the four

Lecture #3 (FA19).pptx - ART 2223 – STRUCTURES II...

This preview shows page 1 - 9 out of 35 pages.

ART 2223 – STRUCTURES II LECTURE #3
Image of page 1
Lesson Objectives Distinguish the types of wood products Distinguish the four major lumber classifications Discuss Adjustment Factors for Wood Design
Image of page 2
Wood Construction Wood consists of cellulose and lignin, illustrated in Figure 2.5 Long cellulose fibers give it strength along the grain, while lignin holds the fibers together, providing shear strength and load transfer between discontinuous fibers. The fibers form the strongest part of this matrix
Image of page 3
Wood Construction Structural Elements Timber materials consist of sawn or engineered (manufactured) lumber. Engineered lumber includes glued laminated timber, SCL, I-joists, and structural panels Lumber\Solid-Sawn: Standard size structural lumber cut directly from logs Full sawn, rough sawn, and dressed Classifications of Lumber Boards: 3/4“ x 2” to 1 1/2“ x 16” Dimension Lumber: 2” x 2” to 4 1/2” x 16” Timber: 5” x 5” and Larger
Image of page 4
Adjustment Factors for Dimensional Lumber Allowable stresses, F′, are found by multiplying the design values listed for a given species of wood from Table 4A and 4B of the National Design Specifications Supplement by the applicable factors
Image of page 5
Wood Construction Structural Elements Glue-Laminated: Glued laminated timbers are made of nominal 2x material, glued together flatwise, thereby making larger members Manufacturers economize by placing higher-quality material in the top and bottom laminations (lams or layers), where bending stress is greatest, and lower-quality, less-expensive woods for the middle lams, where shear is dominating Glued laminated members are available in a variety of curved shapes, making them popular for gymnasiums, natatoriums, and places of worship
Image of page 6
Adjustment Factors for Glued- Laminated Lumber Allowable stresses, F′, are found by multiplying the design values listed for a given species of wood from Tables 5A, 5B and 5C of the National Design Specifications Supplement by the applicable factors
Image of page 7
Wood Construction Structural Elements SCL is made of layers or strands of wood, glued together SCL is often used to replace solid sawn joists and light beams and, in recent years, has become available in column form It encompasses four product types: Laminated veneer lumber (LVL) - We use LVL for beams, joists, headers, and for I-joist flanges » Resembling plywood, it is thicker, and the lams are all parallel, as shown in Figure 2.10 » It comes in 1x in (44.5 mm) thicknesses and depths ranging from 5x to 18 in (140–457 mm)
Image of page 8
Image of page 9

You've reached the end of your free preview.

Want to read all 35 pages?

  • Winter '20
  • Lumber, Engineered wood, Wood Construction, Composite Lumber

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern

Stuck? We have tutors online 24/7 who can help you get unstuck.
A+ icon
Ask Expert Tutors You can ask You can ask You can ask (will expire )
Answers in as fast as 15 minutes