Details
I want to make a wardrobe, and I'm considering designing it without the wardrobe's backside. Instead, I plan to attach shelves directly to the timber joists behind the wall. However, if the analysis shows that it is infeasible (or I do not like the final design), I will add the backside.
Suppose I know the parameters of the joists (timber type, thickness, width, Young's modulus, and anything else) and can control the material for the shelves. I wish to know how to design fastening for the shelves (which screws to choose, whether to use a cantilever or add a strut, which angle to choose for the strut etc.) In particular, I want to know the terminology required to find the needed parameters and recommendations. I can see recommendations like "Usually shelves are supported like this." However, I want to perform my calculations to decide which load I want them to bear and choose the look I like the most.
For example, I can perform a beam calculation to determine stress and deflection because timber plate analysis is more complicated. Nevertheless, if required, I can use open-source applications (or write my own solver) for a plate (I already ran simulations in FreeCAD). I also suppose timber can bear only specific screws (for example, screwing an M10 screw in 12mm thick timber can crack the wooden plate; from the Wood Handbook, I understood that the distance from the screw to the timber surface must be at least a half of its diameter) — I believe there are tables or computations for compatibility of screws and plates.
Requirements
Regarding the load, I am unsure whether I want a shelf to bear a uniformly distributed load of 5-10 kilograms or be able to hold up to 50-80 kilograms if somebody wants to use them as a ladder. If I like the design that allows them to hold higher loads, I will probably go for it.
The expected sizes are 40-60cm by 50-60cm. The thickness is the variable to be determined.
Resume
I think my question can be split into smaller ones:
- How to choose the right size and material for the timber shelf considering the load and screw position?
- How to calculate the best position of the screws?
- How to choose the suitable screws considering the shelf size and material?
- How to choose the optimal parameters of a strut and whether it's needed?
The questions depend on each other, which is messy. Nonetheless, shelf design is an old problem, and default approaches with computations have already been made. Therefore, I would also appreciate a list of possible designs with parameters and formulae to compute the recommended maximum load and materials parameters.
