need help to understand some basics of your trade

[ginjko]

hello guys I am a carpenter and I do a lot of welding for myself and i like building a lot of staff. But I got no real idea of material resistance and I always choose my sections according to my intuition and empirical experimentation. I know I tend to choose to big and to build to tough for the job most of the time and as a result i get extra costs and excessive weight.
I want to build an other drop slide fridge with a friend like this one
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you pull on the Handle, it lifts the rest plate and put the fridge you have fitted in ther level with the drawer slides so you can put it back.
We have a lot of aluminum offcuts and we want to use alloy for the new one.
As you can see the handle is mounted on a flat bar which is going to take all the weight when we lift the fridge.
I have been looking a few hours on the web to know how to calculate the resistance needed but i can t find it. Way to technical for me.
I can calculate the force applied on each point of this bar myself no worries but what i do not know is how to predict what will happen to this bar depending of the size of its section and ultimately its shape I know i can strengthen it by bending it to a L shape.
What know is that if the force applied is to big my bar is going to twist then bend.
Could somebody point me in the right direction as for what to look for witch formula, witch material properties to look for and how to use them
I know I gonna have to use stiffness strength and elasticity, but how ?
Any help would be greatly appreciated.

[Kelly_Bramble]

First, I would like to say that over engineering the materials is not a bad practice.

i do not know is how to predict what will happen to this bar depending of the size of its section and ultimately its shape I know i can strengthen it by bending it to a L shape.

To estimate which cross section of material is stronger in bending I would look at the section properties of the structural shape.

See Section Modulus Properties Equation Calculators The larger the section modulus (moment of inertia), the more capable (less deflection) the structural section will exhibit.

Also, see: Properties of Materials