Peridynamics (PD), a non-local generalization of classical continuum mechanics (CCM) allowing for discontinuous displacement fields, provides an attractive framework for the modeling and simu- lation of fracture mechanics applications. However, PD introduces new model parameters, such as the so-called horizon parameter. The length scale of the horizon is a priori unknown and need to be identified. Moreover, the treatment of the boundary conditions is also problematic due to the non- local nature of PD models. It has thus become crucial to calibrate the new PD parameters and assess the model adequacy based on experimental observations. The objective of the present paper is to review and catalog available experimental set-ups that have been used to date for the calibration and validation of peridynamics. We have identified and analyzed a total of 39publications that compare PD-based simulation results with experimental data. In particular, we have systematically reported, whenever possible, either the relative error or the R-squared coefficient. The best correlations were obtained in the case of experiments involving aluminum and steel materials. Experiments based on imaging techniques were also considered. However, images provide large amounts of informa- tion and their comparison with simulations is in that case far from trivial. A total of 6publications have been identified and summarized, that introduce numerical techniques for extracting additional attributes from peridynamics simulations in order to facilitate the comparison against image-based data. Keywords Peridynamics ·benchmark problems ·validation ·experimental data ·fracture mechanics ·wave propagation ·visualization techniques 1 Introduction Peridynamics [112] provides a novel framework for the modeling and simulation of fracture mechanics applications. Peridynamics (PD) can be viewed as a non-local generalization of classical continuum mechanics (CCM), in which the mechanical behavior is modeled in terms of an integral equation of the displacement field rather than by a partial differential equation. The general framework for peridynamics can be further classified into two approaches: 1) APREPRINT - DECEMBER 4, 2021 bond-based PD [112, 116] and 2) state-based PD [117]. In all cases, the PD formulation allows for discontinuous displacement fields, which may be seen as an attractive feature of the method for the treatment of problems dealing with fracture mechanics. Another advantage of PD is that failure phenomena, like in molecular dynamics or atomistic lattice models, can be explicitly included in the constitutive models. In other words, no other external criterion is needed within the peridynamics framework for modeling the initiation and growth of cracks, in contrast to continuum models. This implies that PD is well suited for the simulation of fracture mechanics applications initially devoid of cracks. We refer to [10, 86] for a general description of PD and to [115] for a review of its advantages. Although the PD framework appears to be a promising approach for many problems in solid mechanics, a collective effort remains to be done to validate the bond-based and state-based constitutive models in order to gain confidence in the approach’s predictability and reliability. In particular, PD introduces new parameters, such as the so-called horizon, that are a priori unknown and need to be identified. Both calibration and validation processes require experimental data to assess model’s adequacy and predictability [40, 41]. Another challenge is the treatment of boundary conditions in the case of non-local models. For example, boundary traction does not naturally appear in the non-local formulation [87], which implies that external loads should be applied in a manner different from that in classical continuum mechanics. The main objective of this survey paper is to review and catalog the available experimental data that have already been used in the literature for the validation of peridynamics models and simulations. Our goals are essentially to overview the experimental setups and observables that have been achieved so far and to summarize the validation results presented by the authors, if available. The experiments are classified here into three main categories: 1) the first category is concerned with dynamical experiments that involve wave propagation phenomena; 2) the second category lists the experiments that focus on characterizing the initiation and growth of cracks for various materials; 3) the last category gathers the experiments whose outputs are digital images of observed phenomena. This classification was arbitrarily chosen to simplify the experiment’s presentation. The experimental data has been classified by type: 1) scalar values of observables; 2) scalar functions of input param- eters; 3) and digital images. We report the relative error between experiments and predictions for scalar observables. We estimate the so-called coefficient of determination R-squared [25], also referred to as the Pearson correlation co- efficient R, between the data and model predictions for scalar functions, like series of points. Data stored in the form of images provide a large amount of information, which makes comparison with simulations less trivial. It may be necessary to develop advanced visualization methods [59, 60, 139] to take full advantage of the richness of imaging techniques and be able to fully compare the results from non-local model simulations such as those obtained from peridynamics or molecular dynamics. We think that these methods are beneficial for the community and therefore presented existing methods, e.g.extraction of fragments or crack surfaces. We hope that this survey will provide a useful resource for those interested in the validation of PD models. We also believe that such a contribution could lead to the definition of benchmark problems and experiments for the analysis of PD simulations. This has been in fact the source of motivation for writing such a paper. The paper is structured as follows: Section 2 presents some preliminaries, in particular the approach that we followed to collect the publications relevant to the survey and a brief description of the method to estimate the coefficient of determination R-squared. Section 3 presents the list of dynamical experiments based on wave propagation phenomena for the validation of crack propagation and Section 4 reviews the experiments used for the validation of crack initia- tion/propagation. Section 5 reports in a concise fashion the relative error or the coefficient of determination for each of the previous experiments that provide a confidence level in the validity of the peridynamics models. Section 6 describes advanced visualization techniques and methods for extract additional attributes for comparison against experimental data. Section 7 provides conclusions and perspectives on the state-of-the-art in the validation of peridynamics models. 2 Preliminaries 2.1 Literature search strategy Our objectives in this paper were to find published articles dealing with the validation of peridynamics models based on experimental data, either in the form of observational data or digital images.