Timber Design

16問 • 1年前

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A timber has a circular cross section having a diameter of 250mm. It has a simple span of 4m. NSCP specs. states that in s circular beam the strength is equal to the strength of square section having the same area. Allowable stresses of wood are as follows: Shearing stress parallel to the grain, fy = 1.73 MPa Bending stress, fb = 16.5 MPa Allowable deflectiono = 1/240 of span Modulus of elasticity of wood = 7.31 GPa [object Object] 1. Calculate the maximum uniform load so that the allowable shear stress parallel to the grain is not exceeded?

28.31 KN/m

A timber has a circular cross section having a diameter of 250mm. It has a simple span of 4m. NSCP specs. states that in s circular beam the strength is equal to the strength of square section having the same area. Allowable stresses of wood are as follows: Shearing stress parallel to the grain, fy = 1.73 MPa Bending stress, fb = 16.5 MPa Allowable deflectiono = 1/240 of span Modulus of elasticity of wood = 7.31 GPa [object Object] 2. Calculate the maximum uniform load so that the allowable bending stress is not exceeded?

14.95 KN/m

A timber has a circular cross section having a diameter of 250mm. It has a simple span of 4m. NSCP specs. states that in s circular beam the strength is equal to the strength of square section having the same area. Allowable stresses of wood are as follows: Shearing stress parallel to the grain, fy = 1.73 MPa Bending stress, fb = 16.5 MPa Allowable deflectiono = 1/240 of span Modulus of elasticity of wood = 7.31 GPa [object Object] 3. Calculate the maximum uniform laid so that the allowable deflection is not exceeded?

7.34 KN/m

4-6. The T-section shown is formed by joining two rectangular pieces of wood together. The beam is subjected to a maximum shearing force of 60kN. [object Object] 4. Calculate the moment of inertia about the neutral axis in mm?

10.573 x 106

4-6. The T-section shown is formed by joining two rectangular pieces of wood together. The beam is subjected to a maximum shearing force of 60kN. [object Object] 5. Calculate the shearing stress at the neutral axis?

3.28 Mpa

4-6. The T-section shown is formed by joining two rectangular pieces of wood together. The beam is subjected to a maximum shearing force of 60kN. [object Object] 6. Calculate the shearing stress at the junction between two pieces of wood?

31.78 Mpa

7-9. A rectangular wooden beam has a span of 6m and carries a total uniform load of 25 kN/m including its own weight. The beam is made up of 80% stress grade Apitong with allowable stresses shown below. Allowable Stress for Apitong is 80% Stress Grade Allowable bending = 16.5 Mpa Compression parallel to grain = 9.56 Mpa Compression perpendicular to grain = 2.20 Mpa Shear parallel to grain = 1.73 Mpa Modulus of elasticity = 7310 Mpa Allowable deflection 7. Which of the following gives the smallest dimension of beam that will not exceed the allowable bending stress?

220 x 440 mm

7-9. A rectangular wooden beam has a span of 6m and carries a total uniform load of 25 kN/m including its own weight. The beam is made up of 80% stress grade Apitong with allowable stresses shown below. Allowable Stress for Apitong is 80% Stress Grade Allowable bending = 16.5 Mpa Compression parallel to grain = 9.56 Mpa Compression perpendicular to grain = 2.20 Mpa Shear parallel to grain = 1.73 Mpa Modulus of elasticity = 7310 Mpa Allowable deflection 8. Which of the following gives the smallest dimension of the beam that will not excess the allowable shearing stress?

200 x 400 mm

7-9. A rectangular wooden beam has a span of 6m and carries a total uniform load of 25 kN/m including its own weight. The beam is made up of 80% stress grade Apitong with allowable stresses shown below. Allowable Stress for Apitong is 80% Stress Grade Allowable bending = 16.5 Mpa Compression parallel to grain = 9.56 Mpa Compression perpendicular to grain = 2.20 Mpa Shear parallel to grain = 1.73 Mpa Modulus of elasticity = 7310 Mpa Allowable deflection 9. Which of the following gives the smallest dimension of the beam that will not excess the allowable deflection?

250 x 500 mm

A timber column height of 5m has a square cross-section of side 200mm. It is supporting a load of 320 KN. At mid-height a recess is cut in one face of the column to receive a girt. The cut is 250mm vertical and 50mm deep. Calculate the strain energy in Newton-meter if E=1360 Mpa

478.431

Determine the most economical commercial size of a Yakal beam which can replace a 100m x 200mm Apitong beam. The allowable bending stress for Apitong and Yakal are 13.8Mpa and 19.3 Mpa, respectively. Assume lateral stability is not a problem.

50 x 250 mm

A cantilever wooden beam 60mm wide by 200mm high and 6m long carries a load that varies uniformly from zero at the free end to 1000 N/m at the wall. Compute the flexural stress in a fiber 40mm from the top of the beam at a section 3m from the free end.

1.125 Mpa

A 2”x4”1” lumber is:

⅔ bd ft

What do you call the type of cut that is parallel to the axis of the tree and radially across the annual rings?

Quarter sawing

What type of defect in lumber is described as the longitudinal cracks following the growth rings? This develops prior to cutting the lumber and sometimes causeb by heavy winds.

Shake

True/ False: Wood is stronger when load is ⊥ to the grains

False

BU2 Quiz 100

Mat · 30問 · 1年前

BU2 Quiz 100