oriol
Well-Known Member
Hi!
The vast majority of frames I build, is using Ducal/St 52, which seems to be the closest thing available in here to Chromolly, with thin walls. The local supplier provides some specifications;
Elastic limit 48 kg/mm2
Maximum elongation 6% minimum,
With this parameters, it seems to be possible to calculate the modulus of young (E) of Ducal using Hooke's law;
elongation = F/(S*E)
E = F/(S*elongation)
First I convert kg/mm2 to N/m2;
48 kg/mm2*1*10^6mm2/1m2*9,81N/kg = 4,707192*10^8 Pa, or^4,7 Mpa
Then I convert 6% elongation to elongation/original length;
6/100 = 3/50 = 0,06
Then I subsitute the values into Hooke's equation;
E = 4,707192*10^8 Pa / 0,06 = 7,848*10^9 Pa or 7,848 Gpa
This value seem two orders of magnitude below, to what might be realistic. Since the modulus of young of steel is 210 Gpa, and tin is 40 Gpa.
I am not able to tell what is wrong with those numbers? Any thoughts will be greatly appreciated!
Cheers,
Oriol
The vast majority of frames I build, is using Ducal/St 52, which seems to be the closest thing available in here to Chromolly, with thin walls. The local supplier provides some specifications;
Elastic limit 48 kg/mm2
Maximum elongation 6% minimum,
With this parameters, it seems to be possible to calculate the modulus of young (E) of Ducal using Hooke's law;
elongation = F/(S*E)
E = F/(S*elongation)
First I convert kg/mm2 to N/m2;
48 kg/mm2*1*10^6mm2/1m2*9,81N/kg = 4,707192*10^8 Pa, or^4,7 Mpa
Then I convert 6% elongation to elongation/original length;
6/100 = 3/50 = 0,06
Then I subsitute the values into Hooke's equation;
E = 4,707192*10^8 Pa / 0,06 = 7,848*10^9 Pa or 7,848 Gpa
This value seem two orders of magnitude below, to what might be realistic. Since the modulus of young of steel is 210 Gpa, and tin is 40 Gpa.
I am not able to tell what is wrong with those numbers? Any thoughts will be greatly appreciated!
Cheers,
Oriol
