## 1 Introduction
Other researchers have used various continuum models employing 2D or 3D solid elements to predict 3D-printed specimen behavior. They have focused on creating material models of various reinforced and unreinforced plastics, including isotropic [25; 26; 27; 28], orthotropic [29; 30], viscoelastic [31; 32; 33; 34; 35], elastic-plastic [31; 33; 35; 36; 37; 38], damage [35; 37; 38] and hypereelastic [31; 39]. Some have used modelling strategies including multiscale or representative volume element (RVE) simulation [28; 29; 30; 32; 33; 37], cohesive elements [37], XFEM [33], embedded elements [26], or the explicit inclusion of voids [27; 31]. Though continuum models have been successfully applied to the behavior of FDM parts, such models do not accurately capture the parts' structure, which is not homogenous but consists of voids, beads, and inter-bead bonds. While multiscale modeling can incorporate this heterogeneity, none of the papers above took into account the thermal loading on their modeled parts during printing, which can induce significant residual stresses. Also, while one of the strengths of FDM is the ability to fabricated complex structures, the vast majority of the papers above looked at simple geometries, either coupons or plates. Sequentially coupled thermal mechanical analysis (SC-TMA) is one way to simulate the effects of the printing process and printing-induced stresses. This method was first applied to the FDM of polymers by [PERSON] [40] and [PERSON] and [PERSON] [41]. As interest in 3D modelling increased, commercial finite element programs incorporated built-in tools for using this method to simulate FDM, which explicitly model the deposition and thermal behavior of material during printing. Some typical characteristics of these commercial codes are small strains, no self-weight, rectangular bead cross-sections, perfect bond between beads, part fixity to the bed, and treatment of the part as a continuum. Some authors used these tools with material properties provided by the software to model tensile coupons or cubes [42; 43; 44; 45; 46]. While SC-TMA can more closely simulate the stress state of a part, it hasbeen shown that 3D printing also affects the strength of parts compared to neat polymer or traditional manufacturing methods and so using general material properties is most likely inaccurate. [PERSON] et al. [47] manufactured and modeled the printing of two complex geometries of ABS (termed planar spring and bridge) employing SC-TMA in ABAQUS v.2017 using 3D solid brick elements. An elastic-plastic material model was used, with temperature-dependent material properties taken from the literature [47]. During printing, the part was fixed to the bed, but once cooled, a portion of the part was released based upon experimental observations [47]. Vertical displacements from the model were compared to those measured after actual printing and agreed relatively well [47]. Similar to [PERSON] et al., [PERSON] et al. [48], [PERSON] et al. [49] and [PERSON] et al. [50] all modeled various geometries (plate and bridge, tensile coupon, and plate, respectively) with an elastic-plastic model with thermally dependent properties using commercial software. All three groups compared measured versus simulated distortions at the edge of the part and errors ranged from 10% to well over 100% [48; 49; 50]. Other groups have also applied SC-TMA to the printing of FDM parts. [PERSON] et al. [51] used SC-TMA in ABAQUS to model the printing and behavior of rectangular prisms of polyurethane-based amorphous thermoplastic using experimentally derived material properties in a linearized thermo-elastic model. Their comparisons between experimental and simulated warpage had a maximum difference of 12% [51]. [PERSON] et al. [52] modeled short carbon fiber PLA square and circular pipes using Digimat AM. Their material model was thermoelastic with parameters determined through experimental testing and included the effects of crystallization [52].