When modeling stranded conductors using SOLID236 or SOLID237 with KEYOPT(1)=0, the applied current density J specified on the BFE command (BFE,,JS) must satisfy the solenoidal condition .

‘Solenoidal’ refers to the closed nature of any real current loop. To be solenoidal, there can be no closed surface inside the model for which the surface integral of current density is nonzero. In other words, a conductor cannot end inside the model; however, conductors can begin or end at the surface of the model. If this condition is not satisfied, the edge-based magnetic analysis can produce erroneous solutions. To make sure that the applied current density is solenoidal, perform a preliminary static electric current conduction analysis to obtain the current density distribution (for example, using electric elements, see Electric Field Analysis). Once the currents are determined, bring them into the magnetic analysis using the LDREAD command.