KNOWN: Thickness, initial temperature and properties of steel plate. Convection conditions at both
FIND: Time required to achieve a minimum temperature.
T = 750C
h = 400 W/m2K
L = 62.5 mm
ASSUMPTIONS: (1) One-dimensional
Selected Midterm I Questions
The figure shows a forklift truck passing over two 15-deg ramps (one for each side) to drive onto a 120 cm-high
loading platform. The truck weighs 44 kN. The distance between the wheels (b-a) is 105 cm. The cross-sections o
1. The bar AC is rigidly attached at its midpoint to another
bar BD as shown. Bar AC is rigidly fixed at its ends.
Diameter of the bars, d, is 20 mm and = 40 cm. The
material is steel with = 207 GPa and = 79 GPa. (a) A
force of = 500 N is then statically
Consider the frame consisting of A and B links that are pinconnected to the primary structure. The force, P, applied
statically at the tip has a normal distribution with an average
of 900 N and a standard deviation of 250 N. The yield strength
of the duct
A 1.2-cm-diameter drill bit is used to make a hole in a plate as shown. During
the drilling operation, an axial force = 1600 N and a torque = 25 Nm
act on the bit. If a horizontal force = 150 N is accidentally applied to the
plate being drilled, (a) what
A vertical pipe with an outside diameter of 300 mm and a wall thickness of 12
mm supports the loads shown in the figure. The loads, and , are slowly
applied and normally distributed with = 900 kN, = 25 kN, = 150
kN, and = 3 kN. The material is a low carbo
The stress state in a mechanical element is shown in the figure.
is two times the value of (both of them are positive). The
material is brittle with = 300 MPa, = 750 MPa. (a) Find
the maximum values of and that will not cause static failure
with a safety
A uniform gap of 0.04 mm surrounds a steel plate
placed in a frictionless rigid cavity as shown in the
figure. According to the maximum shear stress and
maximum distortion energy theories, at what change in
temperature will the plate yield? What is the
The force applied statically at the tip has a normal
distribution with an average of 2000 N and a
standard deviation of 300 N. The yield strength of
the ductile material is 800 MPa on average with a
standard deviation of 30 MPa. What is the
The internal static loads at a critical section along the steel
drive shaft of a ship are calculated as a torque of 3000 N.m, a
bending moment of 2500 N.m in the y direction and a bending
moment of 2400 N.m in the z direction, and an axial
Heat Dissipation and Equilibrium Oil Film Temperature
13.11 Heat Dissipation and Equilibrium Oil Film Temperature
Under equilibrium conditions the rate at which heat is generated within a bearing is
equal to the rate at which heat is carried awa
KNOWN: Thickness, properties and initial temperature of steel slab. Convection conditions.
FIND: Heating time required to achieve a minimum temperature of 500C in the slab.
T = 850C
h = 200 W/m2K
L = 0.0625 m
Steel, Ti = 150C
KNOWN: Diameter and radial temperature of AISI 1010 carbon steel shaft. Convection
coefficient and temperature of furnace gases.
FIND: Time required for shaft centerline to reach a prescribed temperature.
KNOWN: Thermophysical properties and initial temperature of thick steel plate. Temperature of
water jets used for convection cooling at one surface.
FIND: Time required to cool prescribed interior location to a prescribed temperature.
There is no prepared solution for Problem 1.10.
There is no prepared solution for Problem 1.11.
There is no prepared solution for Problem 1.12.
There is no prepared solution for Problem 1.13.
There is no prepared solution for Problem 1.14.
There is no pre
KNOWN: Diameter, resistance and current flow for a wire. Convection coefficient and temperature
of surrounding oil.
FIND: Steady-state temperature of the wire. Time for the wire temperature to come within 1C of its
Selected Midterm I Questions
The figure shows a forklift truck passing over two 15-deg ramps (one for each side) to drive onto a 120 cm-high loading
platform. The truck weighs 44 kN. The distance between the wheels (b-a) is 105 cm. The cross-sections o