Download presentation

Presentation is loading. Please wait.

Published byTerrence Daisley Modified about 1 year ago

1

2
Use spacebar or mouse to advance slides. Problem 4.1 Applied Loads & Reactions Loading up that pickup truck!

3
A 1400-kg pickup truck is loaded with two crates, each having a mass of 350 kg. Determine the reactions at each of the two rear wheels and front wheels.

4
Consider just the pickup truck.

5
Its weight is concentrated at its center of gravity. 1.8 m1.2 m AB 0.75 m

6
This weight is distributed over the two axles, at R A and R B. 1.8 m1.2 m AB RARA RBRB

7
SUGGESTION: Since the loads are given in kilograms with even numbers, it might be best to calculate with kg and convert to Newtons at the end.

8
Analyze as though a simple beam. F = 0 = kg + RA RA + RBRB MB MB = 1400(1.2 m) - R A (3.0 m) RA RA = 560 kg x 9.81m/sec 2 and RB RB = 840 kg x 9.81m/sec m1.2 m AB 0.75 m RARA RBRB

9
The reactions at the wheels are: R A = 5.49 kN R B = 8.24 kN 1.8 m1.2 m AB 0.75 m RARA RBRB

10
Now let’s add some crates to the bed of the truck and determine the reactions at the wheels. 1.8 m1.2 m AB RARA RBRB

11
Each crate has a mass of 350 kg and is positioned as shown. 1.8 m1.2 m AB 0.75 m RARA RBRB 1.7 m2.8 m CD

12
Repeat the same calculations with the added loads as shown. 1.8 m1.2 m AB 0.75 m RARA RBRB 1.7 m2.8 m CD

13
F= 0 = RA RA + RBRB 1.8 m1.2 m AB 0.75 m RARA RBRB 1.7 m2.8 m CD 350 kg 1400 kg 350 kg

14
M B = 1400(1.2 m) - R A (3.0 m) + 350(2.05 m) + 350(3.75 m) 1.8 m1.2 m AB 0.75 m RARA RBRB 1.7 m2.8 m CD 350 kg 1400 kg 350 kg 2.05 m

15
M B = 1400(1.2 m) - R A (3.0 m) + 350(2.05 m) + 350(3.75 m) 1, ,312.5 = R A (3.0 m) 3,7100 kg-m = R A (3.0 m) 3,7100 kg-m = R A (3.0 m) R A = 1, kg x 9.81 m/sec 2 R A = kN

16
F= 0 = RA RA + RBRB R B = RARA RB RB = 2100 kg kg RB RB = kg x 9.81 m/sec 2 RB RB = 8.47 kN AB R A = kNR B = 8.47 kN 350 kg 1400 kg 350 kg

17
Final results are shown. Each rear wheel = 6.07 kN Each front wheel = 4.24 kN AB R A = kNR B = 8.47 kN 350 kg 1400 kg

Similar presentations

© 2017 SlidePlayer.com Inc.

All rights reserved.

Ads by Google