HW _5 Solutions - ANS(a From slide 27 in the course notes...

Info icon This preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
CEE 3020 Civil Engineering Materials SOLUTIONS Question 1 A small block of southern pine lumber weighs 140g when green. Oven dry, the block weighs 50g. (a) Calculate the moisture content of the green wood. ANS. % 180 100 50 50 140 100 (%) = × - = × - = g g g M M M MC ovendry ovendry actual (b) Estimate the mass of the block of wood when its moisture content reaches its fiber saturation point. Assume the fiber saturation point coincides with a 30% moisture content. ANS. g M g g M M M M MC fsp fsp ovendry ovendry actual 65 % 30 100 50 50 100 (%) = = × - = × - = Question 2 A Ponderosa Pine wood beam (2x2” in cross section), simply supported at both ends, is subjected to a center point load of 100 lbs. If the span (L) of the beam between the supports is 60”, (a) determine if the beam will fail (b) if the beam does not fail, determine deflection of the beam at mid-span.
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: ANS. (a) From slide 27 in the course notes on wood, we know the flexural strength of this species is 9200 psi. We also know that the M max will occur at the center span – for this loading condition – and will be PL/4 or 1500 in.-lbs. psi 125 , 1 ) 2 ( 12 1 ) 1 ( 1500 4 max = = σ which is considerably less than the strength, so the beam will not fail (b) " 27 . ) 2 ( 12 1 ) 10 26 . 1 ( 48 ) 60 ( 100 48 4 6 3 3 = = = = x EI PL deflection δ Question 3 How is the strength of wood generally affected by: (a) its moisture content (b) its specific gravity (c) temperature (d) loading rate (e) duration of loading (f) the presence of defects ANS. See your course notes and textbook for solutions....
View Full Document

{[ snackBarMessage ]}

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