In this video you will understand different types of mechanical load and 3 main types of stress.
Any component, no matter how simple or complex, has to transmit or sustain a mechanical load of some kind. There are mainly 3 types of load that you normally apply on a mechanical componenet.
1.dead" load - Dead load is mainly a load which is only applied once and stays there for a long time for example wall, columns, beams, Floor, roof etc.
2. live" load - A load that changes and moves like vehicles on a bridges, people walking on the first floor.
3. shock” load- It's a load that is applied all of a sudden. for example using a hammer on nails . or when car crashes in to another car in accidents is passes througe an impact test.
Now to understand how these load impacts the component we need to see what happens in atomic structure.
Now Let's understand Stress.
When a load is applied to a component it undergoes a deformation. it does not matter how strong is the metal or how small or soft load is applied.
Now based on the metal. and amount and type of the load applied it will wither deform or break. If deformation disappear once load is removed it is called elastic deformation and if deformation is permenent then it is called plastic deformation.
Now this deformation is measured by the term "Strain"
When you apply load to the component it affects the atomic structure of the component. Even though Atoms are round they are organised in a certain structure and pattern in the metal. to explain this check this video where all ball like structure is organised in a sample. even thoughe they are round they form certain parrerns , Which gets affected when load or heat is applid to the atom. These atoms are connected to each other with the metalic bond.
So stress is nothing but the resistance to deformation due to metalic bond when load is applied. That is why stress is measured by Force applied divided by area on the force applied.
Now based on the applied stress we can understand how the material will behave under load.
There are mainly 3 types of applies stress.
1. Tensile stress
2. Compressive stress
3. shear stress
Tensile stress is a stress where we understand how well the material will do when we try to pull the material apart by applying force to 2 opposite sides.
Compressive stress is a complete opposite where we try to press material towards each other by applying opposite force,
shear stress is something where we see the resistance when we try to slide 2 layers of the material accross each other.