# Shared Flashcard Set

## Details

Mech 323
Mechanical design of gears, shafts, etc. for MECH 323 at Queen's University.
37
Mechanical Engineering
04/14/2016

Term
 What is the module equation?
Definition
 d = mN, where d is pitch diameter, m is module, N is number of teeth
Term
 What is the gear ratio equation?
Definition
 m_G = (Ngear/Npinion) = (Tgear/Tpinion) = (w_pinion/w_gear) = (d_gear/d_pinion)
Term
 What is the definition of pressure angle?
Definition
 Angle between horizontal and tangent to both tooth curves OR angle between pressure line and tangent to both pitch circles
Term
 What is the procedure to determine Ngear and Npinion without interference?
Definition
 1. Determine desired gear ratio (m_G) 2. Select pressure angle and tooth type (full depth vs. stub) 3. Use Npinion equation to find the MINIMUM 4. Use the gear ratio to determine Ngear and check that Ngear is less than the MAXIMUM value given by the Ngear equation 6. Select module m to determine pitch diameters
Term
 How do you find the tangential and radial forces transmitted to the pinion and gear?
Definition
 F_t_gear = F_t_pinion = (T_g/r_g) = (T_p/r_p) F_r_gear = F_r_pinion = (F_t)tan(phi) where phi is pressure angle
Term
 What are the stress and strain definitions in 1D?
Definition
 stress = (force/area) strain = (change in length/original length)
Term
 What are the stress and strain definitions in 2D? What is the stress-strain relationship in 2D?
Definition
 Normal stress: Force acting normal to area/area Shear stress: Force tangential to area/area Normal Strain: Change in length/original length Shear strain: Total change in a right angle Normal stress in x = E*(Normal strain in x) (Normal strain in y)*E = -v*(Normal stress in x) where v is Poissons ratio
Term
 What are the stress-strain relationships in 3D?
Definition
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Term
 What are the strain definitions in 3D?
Definition
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Term
 What are the equilibrium equations in 3D?
Definition
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Term
 What are the definitions of base units and derived units?
Definition
 Base units: Three units that are explicitly chosen Derived units: Unit that is defined in terms of base units[image]
Term
 What are the key differences between stress and strength?
Definition
 Stress: A state property at a specific point in a bodyStrength: An inherent property of a material (can be dependent on other factors)
Term
 How do principal stresses change when the coordinate system is rotated by an angle theta?
Definition
 They don't. Principal stresses are invariant under a coordinate transformation.[image]
Term
 What are the major differences between ductile and brittle material?
Definition
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Term
 What are the Von Mises stress equations?
Definition
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Term
 What is the max shear stress theory and when does it predict failure? (Hint: Stress intensity)
Definition
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Term
 Compare and contrast MSS and DE theories.
Definition
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Term
 Summarize the various failure theories for ductile and brittle material in chart form.
Definition
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Term
 What are the 3 stages of fatigue development?
Definition
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Term
 What is the procedure to find Kf for a given geometry?
Definition
 1. Find Kt for the given geometry2. Find q for the material and notch radius3. Kf = 1+q(Kt-1)OR2. Find neuber constant (sqrt(a)) using equationNOTE: only for reversed bending or axial, Sut must be in kpsi and sqrt(a), sqrt(r) in sqrt(in.) (690MPa = 100 kpsi)3. Kf = 1+(Kt-1)/(1+sqrt(a/r))
Term
 What is the relationship between load intensity, shear force, and bending moment?
Definition
 q = dV/dx = (d^2)M/dx^2where q = externally applied load intensityV = internal shear forceM = internal bending moment
Term
 What are the relationships between V (internal shear force), M (internal bending moment), shear stress and bending stress?
Definition
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Term
 How do you calculate the shear stress due to an internal torque?
Definition
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Term
 Compare externally applied axial force, cencentrated moment, concentrated force, distributed load, and pure torque in terms of the internal loads and stresses they cause. Also show a stress distribution at the cross section and equation for each external load.
Definition
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Term
 Explain how a constant bending moment can cause cyclical completely reversed bending on a rotating shaft.
Definition
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Term
 For a constant 2D external bending moment applied to a rotating shaft, determine Ma and Mm at a given critical point. Assume Mxy and Mxz represent the magnitude of the bending moment in the XY and XZ planes respectively.
Definition
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Term
 What are the characteristics of a deep groove ball bearing?
Definition
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Term
 What are the characteristics of a double row deep groove ball bearing?
Definition
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Term
 What are the characteristics of an angular contact ball bearing?
Definition
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Term
 What are the characteristics of cylindrical roller bearings?
Definition
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Term
 What are the characteristics of tapered roller bearings?
Definition
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Term
 What are the characteristics of double row tapered roller bearings?
Definition
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Term
 What are the characteristics of thrust tapered roller bearings?
Definition
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Term
 What are the rules for good design practice when arranging bearings?
Definition
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Term
 What is the definition of bearing rating life?
Definition
 1. Number of revolutions at which 10% of a random sample of bearings are expected to fail.2. Hours of operation at constant speed that 90% of a sample can be expected to reach without failure.
Term
 What is the relationship between applied radial bearing load F and bearing life L?
Definition
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Term
 What is the procedure for determining the life of a bearing subjected to axial thrust and radial loading?
Definition
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