This paper presents a comparative study of the tensile mechanical behaviour of pieces produced using the Fused Deposition Modelling (FDM) additive manufacturing technique with respect to the two types of thermoplastic material most widely used in this technique: polylactide (PLA) and acrylonitrile butadiene styrene (ABS). The aim of this study is to compare the effect of layer height, infill density, and layer orientation on the mechanical performance of PLA and ABS test specimens. The variables under study here are tensile yield stress, tensile strength, nominal strain at break, and modulus of elasticity. The results obtained with ABS show a lower variability than those obtained with PLA. In general, the infill percentage is the manufacturing parameter of greatest influence on the results, although the effect is more noticeable in PLA than in ABS. The test specimens manufactured using PLA perform more rigidly and they are found to have greater tensile strength than ABS. The bond between layers in PLA turns out to be extremely strong and is, therefore, highly suitable for use in additive technologies. The methodology proposed is a reference of interest in studies involving the determination of mechanical properties of polymer materials manufactured using these technologies.

The lack of specific standards for characterization of materials manufactured by Fused Deposition Modelling (FDM) makes the assessment of the applicability of the test methods available and the analysis of their limitations necessary; depending on the definition of the most appropriate specimens on the kind of part we want to produce or the purpose of the data we want to obtain from the tests. In this work, the Spanish standard UNE 116005:2012 and international standard ASTM D638–14:2014 have been used to characterize mechanically FDM samples with solid infill considering two build orientations. Tests performed according to the specific standard for additive manufacturing UNE 116005:2012 present a much better repeatability than the ones according to the general test standard ASTM D638–14, which makes the standard UNE more appropriate for comparison of different materials. Orientation on-edge provides higher strength to the parts obtained by FDM, which is coherent with the arrangement of the filaments in each layer for each orientation. Comparison with non-solid specimens shows that the increase of strength due to the infill is not in the same proportion to the percentage of infill. The values of strain to break for the samples with solid infill presents a much higher deformation before fracture.

When there is a social consensus that industrial assets are in fact heritage elements of cultural interest, their conservation and reuse must be considered with approaches that offer greater guarantees and that prevent their exposure to aggressive actions. In order for this to materialise, many aspects must be included in the decision-making process, from the characteristics of an asset and its surroundings, to the valuable aspects that distinguish it and that must be protected. This study aims to develop tools that guide the decision-making process regarding the most appropriate activity for each specific case study. Multicriteria Decision Support Techniques are evaluated as adequate support to create a proposal that fulfils these objectives. Furthermore, the Analytic Hierarchy Process is adapted to develop methodologies for assessing both the heritage value and the most compatible uses according to the characteristics of the asset. Subsequently, they are connected and such considerations regarding the heritage value of the asset are incorporated into the final decision. The tools developed are then applied to a case study to test their performance, assess their usefulness, and identify possible applications and future developments.

Additive manufacturing processes and products are very present in the current productive landscape, and in fact these technologies have been one of the most intensively studied and improved during the last years; however, there is still no defined and homogeneous regulatory context for this field. In this work, a thorough review of the main general and specific regulatory developments in design, materials and processes standards for additive manufacturing has been carried out, with special attention to the standards for mechanical characterization of polymer-based products. In many cases standards developed for other productive contexts are identified as recommended references, and some contradictory trends can be identified when different documents and previous experiences are consulted. Thus, as it is logical considering that all these technologies are involved in an intensive and continuous evolution process, there is a certain lack of clarity regarding the standards to be considered. This work aims to contribute to clarify the current standardization context in additive manufacturing and provide some guidelines for the identification of appropriate standards. The paper also emphasizes that the key for next regulatory developments in mechanical testing is to develop standards that consider particular AM processes along with materials. Moreover, a great gap between available standard about additive technologies based on metallic materials and polymer materials during the last years has been detected. Finally, the provided overview is considered of interest as support for research and practice in additive manufacturing, and both in intensive productive scenarios and for particular users and makers.

Any research in any field needs an initial background, and in the same way, any decision should be supported by previous knowledge and study of the problem and its context. In the case of the industrial heritage, both the study of the typology and the decision making about the actions of conservation and reutilization of its assets must be based on a deep knowledge of the set of elements that the typology includes. All of that refers to the corresponding territory being analyzed, since the intensity and productive tradition will be different between each territory, region, or country. In that context, this paper represents the continuation of the main research line of the authors, and exposes their efforts to develop a useful tool for the study, management, and cultural promotion of the assets related to industrial heritage in Spain through the development of a multi-criteria catalogue of assets. Thus, based on the initial catalogue developed by some of the authors, this paper significantly increases the number of assets considered. In addition, it includes new classification criteria, reviews the observed trends, and establishes the future lines of work and suitable strategies for these kinds of initiatives.

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All complex projects take place in environments of great uncertainty. Maintaining a monitoring and control system from the early stages of execution is a critical factor in the success of this type of project. Large hydroelectric power station construction projects are regarded as highly complex because they are affected by factors such as the risks inherent in a variety of fields of engineering, geology and the environment, the long execution times, and the large number of multidisciplinary activities to be carried out in parallel, among others. These types of projects are commonly affected by cost overruns and delays. This work develops a methodology for the monitoring and control of complex construction projects in the hydroelectric sector that enables a periodical calculation of metrics for physical progress, financial progress, and predictions for costs and durations on completion of the project. The verification of the efficiency of this methodology was based on stochastic simulation models applied to real projects in the hydropower sector. The results showed that the proposed methodology improved efficiency compared with existing traditional methodologies. The proposed methodology allows the simultaneous consideration of costs, deadlines, criticality, and risks of the activities of the analyzed projects and also incorporates multicriteria decision techniques to manage the influence of key aspects during the development of the project.