Hello!
I am building a conservatory but have problems obtaining a building permit because we need to submit calculations for the dimensions of the timber. Unfortunately, I no longer have my strength of materials books, so I'm stuck and hope there is a kind soul who can help me here!
The span of a beam is 4m, I live in Skåne, the roof's own weight, is there perhaps a standard value to use?
According to the formula for beam deflection
* * * *5 * Q * L
d = -------------------
* * * * 384 * E * I
You should be able to get I from this, and then I am pretty sure you could use this I in another formula and thus calculate if, for example, a K24 45x170 is sufficient. Does anyone know what I'm rambling about? As mentioned, I hope someone can help me because I am completely stuck! Maybe more input data is needed?
I am building a conservatory but have problems obtaining a building permit because we need to submit calculations for the dimensions of the timber. Unfortunately, I no longer have my strength of materials books, so I'm stuck and hope there is a kind soul who can help me here!
The span of a beam is 4m, I live in Skåne, the roof's own weight, is there perhaps a standard value to use?
According to the formula for beam deflection
* * * *5 * Q * L
d = -------------------
* * * * 384 * E * I
You should be able to get I from this, and then I am pretty sure you could use this I in another formula and thus calculate if, for example, a K24 45x170 is sufficient. Does anyone know what I'm rambling about? As mentioned, I hope someone can help me because I am completely stuck! Maybe more input data is needed?
Go to moelven.com/se, select "limträ" and "support och dimensioneringsprogram". With the help of the program, you should be able to calculate a suitable dimension. Whether you can submit it as calculations, I don't know.
You can also visit http://www.byggbeskrivningar.se/dimensionering and calculate, where, unlike Moelven's program, you can find both ordinary construction graded timber and glulam. But as Tror jag fattar writes about whether it's sufficient as a basis for the municipality, I don't know either. But all such programs calculate on basic constructions, so if it's a more advanced conservatory you're going to build, they won't be sufficient.
Calculating the deflection is one thing, but I assume the municipality also wants figures on how high the stress will be. You therefore need to calculate both the section modulus (W) and the moment of inertia (I). Possibly you also need to check the shear stress.
The difficulty, of course, is knowing what values to assume for the modulus of elasticity and permissible tensile, compressive, and shear stress; I don't know that.
The difficulty, of course, is knowing what values to assume for the modulus of elasticity and permissible tensile, compressive, and shear stress; I don't know that.