Why Do We Need Washers in Bolts?

The explanation was so simple I’m sure that the retention of the said info will last for my lifetime.

Advertisements
wwwDOTdanasrgeDOTtop.jpg
Bolt, nut and washers. Photo from http://www.danasrge.top

I really did not have any idea at all why. It just made sense when my graduate school professor in advanced design of metal structures explained it. The explanation was so simple  I’m sure that the retention of the said info will last for my lifetime.

washersampdryersDOTcom
Bolt anatomy. Photo from http://www.washersampdryers.com

So why?

WASHERS ARE NECESSARY FOR SLIP CRITICAL CONNECTIONS TO HOLD THE JOINED MEMBERS WHERE IT IS SUSCEPTIBLE TO FAIL IN CYCLIC LOADING. THEY FIRMLY HOLD THE MEMBERS TOGETHER SO THAT THEY FUNCTION AS ONE.

For example, a certain member in a steel bridge truss is joined by bolts. Since traffic is a moving load, it generates cyclic loading which is the constant exchange of compressive and tensile stresses in the member. If the connection of joined members which is a weak link, is not designed and detailed properly, it will fail over time under these cyclic loadings. For a more simplistic example, let’s say you’re holding a tie wire (alambre) and you repeatedly bend it back and forth. First it will generate heat, it loses strength in the process until it ruptures.

As the bolt is tightened by applying torque to the head and the nut (the head and the nut are always hexagonal in shape, that is, it has 6 sides) it generates a tensile force in the bolt while the washers provide the surface required for a clamping action (it presses the joined members firmly together) and prevents sliding by means of friction in the base metal.

Simple as it looks, bolt washers play a very vital role in the health of the overall structure where they are employed.

Author: The Romantic Alpha

Aside from physical and intellectual strength, a man is also given a heart to feel and share love and value. Dive into the mind of the alpha, feel his heart beat, and let me carry you with my strong yet gentle hands. I'm continuously innovating myself to be a better man, husband, father, friend, and structural engineer. Love's not overrated. The world needs the true essence of which.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s