RE: [FEMM] Need help in analytical fitting of steel B-H curve

["Dr. Lee Marriott" <Marriott@xxxxxxxxxxxxxx>]

Tsarafidy,

	A simple, but not extremely accurate BH model was developed by J. Brauer (1975).

	Reluctivity = k1*exp(k2*B*B)+k3, derviative d(rel)/dB^2 = k1*k2*exp(k2*B*B).

The equation fits the curve for Rel as a fct of B^2. Three points from the BH curve, one from the linear region, and the other two just below and above the knee are used for the fit.  See "Computer-Aided Analysis and Design of Electromagnetic Devices," by Hoole (1989) for comments and some other BH curve approaches.

	The Rel=fct(B*B)is used in many magnetic FEA formulations for integration using higher order elements.

Lee



-----Original Message-----
From: Tsarafidy RAMINOSOA [mailto:tsarafidy@xxxxxxxx] 
Sent: Monday, April 19, 2004 9:11 PM
To: femm@xxxxxxxxxxxxxxxxxxxxxx
Subject: [FEMM] Need help in analytical fitting of steel B-H curve


Hello All,

I'm searching for an analytical form of a function
with known derivative, other than piecewise
polynomial, fitting B-H curve of a given steel.
Any paper or advice about this will be appreciated.

Thanks in advance.

Tsarafidy.



	

	
		
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