A car, train, bike or transportation vehicle is a type of load.
Snow, rain, sleet or hail is a type of load.
People, animals, and bugs are types of load.
The structure or bridge itself is a type of load.
The weight of the structure itself.
The weight of people, materials, or weather on top of the structure.
A force is a push or pull on an object.
A force can cause an object to accelerate, slow down, remain in place, or slow down.
One of the most famous types of forces is known as gravity. Gravity is the force that attracts a body or object to the center of the Earth.
Another famous force is a Jedi's Force, ya know, THE Force. I like to think we all have the force.
Compression is known as the pushing force. This is the type of force that you often see hydraulic press machines use.
Tension is known as the pulling force or the force that makes things longer. Think of the slime you sometimes make when you are home. Have you ever tried to stretch it as far as it could possibly be stretched? That's when you're using tension!
Torsion is known as the twisting and turning force. Think about a time where you had to dry out a rag. The twist motion you use to squeeze out the water is known as torsion!
Shear is when two forces are going in opposite directions. Think about tectonic plates! Earthquakes and tsunamis happen because two of Earth's plates rub against eachother in opposite directions. That's known as a shear force!
Bending is a force that turns something into a curve or angle. This is the most known type of force since we use it the most often! Think about a time that you've cracked spaghetti into a pot of water. You are using the bending force!
In fact, more than one type of force can act on a bridge at the same time!
There are 5 types of forces that can act on bridges:
Compression
Tension
Torsion
Shear
Bending
All 5 forces can play an important role in the strength and sturdiness of each bridge!
A suspension bridge is the longest type of bridge that often spans over oceans or large areas. This bridge is built with cables for support.
One of the most famous suspension bridges is The Golden Gate Bridge (aka the Full House Bridge!)
Have you ever wondered why some bridges are made of all triangles? Triangles are the strongest shape and they actually make up their own type of bridge! A truss bridge is primarily made of triangles. This bridge is shorter and often covers small bodies of water, highways, or train tracks!
T is for Truss & Triangles!
The types of bridges that can be seen over highways are known as beam bridges. Beam bridges are the cheapest to build and are only built for smaller distances.
If a beam bridge needs to be built over a longer distance, engineers will often use columns to support the bridge. Next time you're on the highway, count how many beam bridges you see!
An arch bridge is the oldest type of bridge built and uses curves and cirles to support heavy forces and weight.
It gets its name from the arch it creates on the bottom of the bridge!
A cantilever bridge can easily be mistaken for a suspension bridge, however, there is a big difference between the two!
A cantilever bridge uses triangles for support, often made of a type of metal, while suspension bridges uses cables for support. Both types of bridges do span over longer distances.
Suspension Bridge
Truss Bridge
Beam Bridge
Arch Bridge
Cantilever Bridge
All 5 bridges are constructured differently, but are built to fulfill the same purpose.
Have you ever wondered why bridges work? Check out this slide shows on strong structures!
Included in the slides is a strong structure enrichment activtity you can complete in the comfort of your own house! All you need is gummy worms/mini marshmallows and some tooth picks!
Students worked on creating a strong structure in class that can hold the force of a brick. Students were only allowed to use gummy worms and tooth picks!
Two 7th grade Kennedy Wildcats were able to figure out how to hold the weight of the brick on their structure by using triangles!
The Engineering Design Process is a series of steps that Engineers must follow in order to solve a problem or need.
There are many different types of Engineers. Here are just a few!
Civil Engineers: engineers who work on structures, buildings, and bridges
Chemical Engineers: engineers would work with chemicals
Biomedical Engineers: engineers who work with medicine and biology
a way to move people or cargo from one place to another
sending, receiving, or understanding a message
the process of building a structure on a site
the process of building a product in a factory