During some ultrasonic non destructive evaluation inspections implying high temperatures conditions, Electromagnetic Acoustic Transducers (EMATs) are very useful because, contrary to conventional piezoelectric transducer, they do not require any coupling fluid and they have the capability to generate a great number of mode propagation by interchanging the geometry of the emitting electromagnetic apparatus. However, the poor transduction between ultrasonic energy and electromagnetic energy must be improved in order to increase the performances of these transducers. This paper aims to develop some new simulation tools in order to be able to make some parametric studies by using semi-analytical models with reasonable time computations sufficiently flexible for dealing with a great number of geometric configurations. In order to achieve this goal, time harmonic eddy current modules already implemented into the CIVA software are firstly extended to time domain and then they are connected to ultrasonic semi-analytical models to provide at low cost of computation the response of the EMAT transducer. This paper presents the different steps of the developments which have been followed to obtain the new functionalities into the CIVA platform.