You can often perform coupled physics simulations using a circuit analogy. Components such as "lumped" resistors, sources, capacitors, and inductors can represent electrical devices. Equivalent inductances and resistances can represent magnetic devices, and springs, masses, and dampers can represent mechanical devices. Mechanical APDL offers a set of tools to perform coupled simulations through circuits. A Circuit Builder is available to conveniently create circuit elements for electrical, magnetic, piezoelectric, and mechanical devices. See Using the Circuit Builder in the Low-Frequency Electromagnetic Analysis Guide for details.

A coupled physics circuit simulation can be performed entirely with lumped elements. However in many instances, due to the distributed nature of the physics component, nonlinearities, etc., a simple "reduced order" element may not be sufficient. The Circuit capability allows you to combine both lumped elements where appropriate, with a "distributed" finite element model in regions where characterization requires a full finite element solution. What allows the combination of lumped and distributed models is a common degree-of-freedom set between lumped elements and distributed elements.

Electromagnetic-Circuit Simulation describes the coupling of electrical circuits with distributed electromagnetic finite element models to accurately model circuit-fed electromagnetic devices.

Electromechanical-Circuit Simulation describes the coupling of electric circuits, an electromechanical transducer, and structural lumped elements to model micro-electromechanical devices (MEMS) driven by electrostatic-structural coupling.

Piezoelectric-Circuit Simulation describes the coupling of electrical circuits with distributed piezoelectric finite element models to simulate circuit-fed piezoelectric devices.

For example problems, see Sample Electromechanical-Circuit Analysis and Sample Piezoelectric-Circuit Analysis (Batch or Command Method).