# mechanical principles

Topics: Force, Shear stress, Continuum mechanics Pages: 4 (1010 words) Published: October 31, 2014

Scenario
You work as a mechanical engineer designing structures; you are required to calculate the forces, stresses and strains required to help with these designs. Task 1 (P1)
Using fig 1 below, calculate magnitude, direction and position of the lines of action of the resultant of the non-concurrent coplanar force system containing forces in different directions. 3810002914650041338502914650044767505143528KN

0028KN
4324350539115500
020000500
47625035433030KN
0030KN

-96202510922015KN
0015KN

-66675015494000 109474050546000
42195756477022KN
0022KN

Using fig 2, calculate the support reactions R1 and R2 of the beam, also determine the balance of the beam. -325755100965Fig 2
R1
R2
6 m
2.0 m
3.5 m
200 N
400 N
W=100 N/m
00Fig 2
R1
R2
6 m
2.0 m
3.5 m
200 N
400 N
W=100 N/m

A copper strut with a diameter of 60mm and length 500mm is carrying a direct uniaxial load of 500N with a young’s modulus of 980KPa. Calculate (a) the direct stress, (b) the percentage strain in the material (c) the change in length of the strut. Task 4 (P3)

A block of material is subjected to a shear force of 300N and is deformed. Find (a) the shear stress and (b) the shear strain. Dimensions
L=130mm H=50mm W=60mm

A component containing two pins is subjected to a combination of direct and shear stress. The pins are 10mm diameter with a UTS of 600MPa and an USS of 400Mpa. Calculate: The factor of safety of the pins when subjected to direct stress. The factor of safety for the pins when subjected to shear stress. Grading criteria for PLC assignment 4

P1 Calculate the magnitude, direction and position of the line of action of the resultant and equilibrant of a non-concurrent coplanar force system containing a minimum of four forces acting in different directions. The criterion P1 requires the solution of a single non-concurrent force system containing a minimum of four active...