## 1 Introduction  
Concerns over Metallic Pipelines Integrity  
It is well known that high-voltage alternate current (HVAC) transmission lines can be the cause of significant electromagnetic interference effects on nearby metallic structures [1, 2]. Coated pipelines for gas or liquid transportation are notable examples of this kind of structure. The resulting currents and voltages can lead to several kinds of unwanted effect. Workers coming into contact with the pipeline are subjected to shock hazards [3]; the connected cathodic protection systems and the pipeline itself can be damaged through accelerated aging and corrosion [4, 5], as well as through perforations of its coating layer [6, 7]. Pipelines can also be harmed by other sources of interference; for example, in recent years a number of works have been devoted to the effects produced by high-voltage direct current (HVDC) systems [8, 9], as well as traction systems [10] and geomagnetic events [11]. Electrical stress on metallic pipelines may be caused by three coupling mechanisms, i.e., capacitive, inductive, and conductive coupling [12]. In this work, we focus on the most common coupling mechanism, i.e., inductive coupling. Overall, researchers have studied this topic for several decades, and many modeling efforts have been made throughout the years. Much of the initial efforts in this field originated from circuital or transmission line approaches based on [PERSON]'s formulae for mutual impedance [13, 14, 15, 16]. These methods are also generally based on performing a discretization of the considered corridor into sets of coupled smaller sections, described by lumped parameters [17]; such circuital approaches are computationally efficient, making them suitable for fast evaluations or parametric studies. In addition, the formulas for the approximate evaluation of mutual impedance have been extended over time to include the physical effects of soils constituted by multiple layers with different electrical resistivity values [18]. Nevertheless, over the years--thanks to the ever increasing availability of computing power--researchers have started to study the problem of pipeline integrity with field-theory methodologies [19; 20]; these techniques are based on directly obtaining an approximated solution to Maxwell's equations for the electromagnetic field and allow accurate analysis of complex geometries and arbitrary material properties. In this way, gradually, models using the boundary element method (BEM) [21] or the finite element method (FEM) [22; 23; 24]--often in conjunction with circuit theory--have also been developed. An account of both recent and historic numerical contributions to inductive coupling modeling can be found in [25]. Several commercial codes dedicated to electromagnetic interference calculations also exist, featuring comprehensive modeling capabilities (also regarding problems related to grounding systems). These are often based on a combination of circuit theory and field methodologies, and allow the user to perform a variety of different analyses. Examples of such code programs include the well-established Elysca [26], CDEGS [27], and XGSLAB [28]. The existing research literature on FEM models for AC interference calculations includes several works dedicated to harmonic analysis [20; 22; 29]. In this work, we describe an initial effort towards the development of a comprehensive FEM-based framework that can also deal with transient interference problems, which--to the best of the authors' knowledge--are currently more commonly assessed with transmission-line based approaches [30]. In addition, we also note that the validated research codes are generally closed-source and not available to other scientists and users in general. For this reason, we introduce FLARE--Finite eLatement Analysis foR Electromagnetics.