SME
College · Engineering
Mechanics of Materials (Solid Mechanics I)
7 topics
Classical (Engineering Mechanics)
Before this course
Topics
Stress and strain
Main lesson
Bolt in single or double shear
Use this for “A 16 mm bolt holds 30 kN in double shear. Find the average shear stress in it.”
Diameter change by Poisson’s ratio
Use this for “A 20 mm steel rod is stretched to a strain of 7.96 × 10⁻⁴, with ν = 0.3. How much does its diameter change?”
Size a rod for a factor of safety
Use this for “A steel rod with σY = 250 MPa must carry 80 kN with a factor of safety of 2. Find its diameter.”
Principal stresses and Mohr’s circle
Use this for “A point carries σₓ = 80 MPa, σᵧ = −20 MPa and τₓᵧ = 40 MPa. Find the principal stresses, θₚ and τₘₐₓ.”
Thin-walled pressure vessel
Use this for “A tank 500 mm in radius with a 10 mm wall holds 2 MPa. Find the hoop and axial stresses,” or the stress in a sphere (σₐ).
Axial loading
Main lesson
Thermal stress in a restrained bar
Use this for “A 1 m steel bar of 1,000 mm² held between two walls warms by 40 °C. What stress builds up, and what force does it put on the walls?”
Bar fixed at both ends
Use this for “A bar between two walls carries 30 kN at 0.4 m from the left wall and 0.6 m from the right. Find each reaction.”
Two materials sharing a load
Use this for “A concrete post with 2,000 mm² of steel bars carries 1,000 kN. How much does the steel take?”
Torsion
Bending and shear
Main lesson
Shear and moment of a uniform load
Use this for “A 6 m simply supported beam carries 10 kN/m. Find V and M 2 m from A, and the largest M.”
Shear stress at the neutral axis
Use this for “A 100 × 200 mm beam carries a 30 kN shear force. Find the largest shear stress.”
Size a beam by its section modulus
Use this for “A beam twice as deep as it is wide carries 45 kN·m at 150 MPa allowed. Find its depth.”
Beam deflection
Main lesson
Sag of a simply supported beam under a uniform load
Use this for “A 6 m steel beam on two supports carries 10 kN/m, with I = 80 × 10⁶ mm⁴. Does its sag stay within L ÷ 360?”
Tip deflection of a cantilever by superposition
Use this for “A 2 m steel cantilever with I = 8 × 10⁶ mm⁴ carries 5 kN at its tip and 2 kN/m along it. How far does the tip drop?”
Deflection anywhere along a cantilever
Use this for “A 2 m steel cantilever with I = 8 × 10⁶ mm⁴ carries 5 kN at its tip. How far has it dropped 1 m from the wall?”
Column buckling
Main lesson
Intermediate columns: the Johnson formula
Use this for “A pinned steel column 1.5 m long has r = 25 mm, A = 2,000 mm² and σY = 250 MPa. Find its critical stress and load.”
Slenderness and Euler’s critical stress
Use this for “A pinned steel column 5 m long has A = 2000 mm² and I = 2 × 10⁶ mm⁴. Find its slenderness ratio and critical stress. Does Euler’s formula apply if σY = 250 MPa?”
Stress transformation, combined loading and pressure vessels
Main lesson
Bending, torsion and axial load on a shaft
Use this for “A 50 mm solid shaft carries 20 kN of tension, a 600 N·m bending moment and an 800 N·m torque. Find the principal stresses and τₘₐₓ at the top.”
An eccentric load on a short post
Use this for “A 150 × 300 mm post carries 120 kN pressing down 40 mm off center along the 300 mm side. Find the stress at each edge.”
Thick-walled cylinder (Lamé)
Use this for “A cylinder with 100 mm inner and 125 mm outer radius holds 30 MPa inside. Find the hoop stress at the bore and compare the thin-wall value.”
Course test
See what you know: 10 questions on this course
New questions each time. Pass to mark it complete.