Important: Use custom search function to get better results from our thousands of pages

Use " " for compulsory search eg:"electronics seminar" , use -" " for filter something eg: "electronics seminar" -"/tag/" (used for exclude results from tag pages)

Thread Rating:
  • 0 Votes - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
Braking Dynamics ppt
Post: #1

Braking Dynamics

.pdf  1Braking Dynamics.pdf (Size: 271.5 KB / Downloads: 38)

hen a vehicle decelerates due to braking forces, normal load is transferred off the rear tires, onto
the front. The differences in tire normal load create differences in peak braking force capability.
In order to design the braking system to utilize each tire in a manner suiting its braking capability,
it is necessary to analyze the dynamics of a braking vehicle.

Braking Stability

The differences in vehicle behaviour when locking either the front or rear axle first during braking
are dramatic, and may singly determine whether a vehicle stops safely or loses control. Thus, the
main concern in braking force analysis and design has been whether the distribution of braking
loads will cause front or rear axle lockup.
In order to investigate the effects of different lockup cases, a simple bicycle model can be used.
During straight line driving and braking, tire loads theoretically exist only in the longitudinal
direction. In reality, small lateral disturbances will exist during straight line braking, due to
small steer angles, non-uniform road surfaces, and aerodynamic loads. The result is that even
straight-line driven vehicles are required to supply lateral traction at the tires in order to remain
moving straight.
The situation where the front tires of the vehicle lock up is represented in Figure 5.1. Subject
to a yaw disturbance, the heading of the vehicle has rotated slightly, while the resultant path of
vehicle travel is still directly forward, in the original direction. The locked up front tires only
create forces in a direction opposite the direction of motion.

Lines of Constant Friction Coefficient

From Figure 5.5 it can be seen that at extreme decelerations the weight transfer to the front
tires increases until the point where there is no load on the rear tires. At this point the braking
force on the rear axle is zero regardless of tire-road friction coefficient. Likewise, during extreme
accelerations it can be seen the front axle tractive force is zero regardless of tire-road friction
Each point on the optimal curve implies that μ
frictionF = μ
frictionR = μfront = μrear = a, and
at each zero point the force is zero for any μ. The result is that straight lines joining the zeroforce
points to any acceleration level on the optimum curve represent lines of constant friction
coefficient, with μT i = a.

Design of Variable Brake Proportioning

Specialized brake pressure valves may be implemented to limit some or all additional pressure to
the rear brakes above a certain pressure level. This allows the designer to create a bi-linear brake
proportioning curve, and achieve higher braking efficiencies overall. The bilinear curve can be
shaped to approximate the optimal braking curve.

Brake pressure limiting valve

A brake pressure limiting valve can be installed inline with the rear brake lines. At a chosen brake
pressure level (intended to correspond to a pre-designed critical deceleration) the limiting valve
allows no additional pressure to pass to the rear brakes (Figure 5.12). Generally the baseline first
segment of the proportioning curve is chosen so that it would intercept the optimal curve at a
deceleration of 0.5g [17].

Marked Categories : a sample seminar on brakes of subject dynamics of machine, the differences in vehicle behaviour when locking either, bracking dynamics ppt file, lines of constant friction coefficient, vehicle weight transfer ppt, seminar topics on differential with ppt in mechanical,

Quick Reply
Type your reply to this message here.

Image Verification
Image Verification
(case insensitive)
Please enter the text within the image on the left in to the text box below. This process is used to prevent automated posts.

Possibly Related Threads...
Thread: Author Replies: Views: Last Post
  anti locking braking system full report seminar topics 6 19,306,227 14-01-2018 04:56 AM
Last Post: SharonJer
  electromagnetic braking system ppt Guest 1 156 14-10-2017 03:13 PM
Last Post: jaseela123
  two wheeler dual braking pdf projects Guest 1 171 10-10-2017 04:20 PM
Last Post: jaseela123
  induction braking system Guest 1 217 09-10-2017 12:06 PM
Last Post: jaseela123
  electrical braking of dc motor ppt Guest 1 171 09-10-2017 11:35 AM
Last Post: jaseela123
  project report on abs braking system in ms word file Guest 1 265 06-10-2017 01:14 PM
Last Post: jaseela123
  fuzzy logic controller on automatic car braking system matlab code Guest 1 165 04-10-2017 02:55 PM
Last Post: jaseela123
  induction braking system synopsis Guest 1 169 04-10-2017 01:05 PM
Last Post: jaseela123
  super magnetic braking systems Guest 1 190 04-10-2017 12:05 PM
Last Post: jaseela123
  ppt of vertical lift mechanism ppt Guest 1 508 04-10-2017 11:56 AM
Last Post: jaseela123
This Page May Contain What is Braking Dynamics ppt And Latest Information/News About Braking Dynamics ppt,If Not ...Use Search to get more info about Braking Dynamics ppt Or Ask Here