Climent Molins

Climent Molins
Universitat Politècnica de Catalunya | UPC · Department of Civil and Environmental Engineering

PhD Civil Engineer

About

141
Publications
54,369
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2,626
Citations
Citations since 2016
47 Research Items
1886 Citations
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20162017201820192020202120220100200300
20162017201820192020202120220100200300
20162017201820192020202120220100200300

Publications

Publications (141)
Article
The post cracking behavior of steel fiber reinforced concrete (SFRC) subjected to direct tensile stresses is strongly related to the distribution and orientation of the fibers in the crack plane, which can be precisely determined using images obtained by computerized axial tomography (CAT). However, these images require processing to relate them to...
Article
Full-text available
Widely used simplified analytical methods for estimating the tensile force in tie-rods are clearly not applicable when they contain significant discontinuities or irregularities. A common example for which this fact becomes relevant in practice is the use of connectors to unify historical ties consisting of several segments. To address this challen...
Preprint
Full-text available
This paper provides a summary of the work done within Phase III of the Offshore Code Comparison, Collaboration, Continued, with Correlation and unCertainty project (OC6), under International Energy Agency Wind Task 30. This phase focused on validating the aerodynamic loading on a wind turbine rotor undergoing large motion caused by a floating suppo...
Chapter
In this paper, the residual strengths and flexural toughness of fibre reinforced concretes (FRC), determined from the load - CMOD response obtained by mean of flexural test conducted according to EN 14651, are related experimentally through non-linear fits, which depend on the fibres content and crack opening. On the other hand, it is experimentall...
Article
The quasi-dynamic mooring line model is a new approach to assess the mooring line tension that considers the static solution of the catenary shape, but updates the distributed vertical force along the mooring line as a function of the external forces, drag and inertial, acting on the line. In this way, an updated apparent weight is applied to the s...
Article
This paper presents an adapted particle swarm optimization model for the electrical layout planning of floating offshore wind farms (FOWFs). A comprehensive model is considered by taking into account the entire wind turbine connection possibilities as well as stochastic wind speed and wind direction and the computation of the wake effect within the...
Article
Full-text available
The EU Horizon 2020 project COREWIND (COst REduction and increase performance of floating WIND technology) has developed two floating platforms for the new International Energy Agency (IEA) Wind 15 MW reference wind turbine. One design – “WindCrete” – is a spar floater, and the other – “Activefloat” – is a semi-submersible floater; both designs are...
Preprint
Full-text available
The EU Horizon 2020 project COREWIND has developed two floating platforms for the new International Energy Agency (IEA) Wind 15 MW reference model. One design-"WindCrete"-is a spar floater, and the other-"Activefloat"-is a semi-submersible floater. In this work the design of the floaters is introduced with their aero-hydro-servo-elastic numerical m...
Conference Paper
LCOE reduction in FOWTs is heading to larger wind turbines in order to increase power production and capacity. NREL and DTU have recently developed a 15MW reference wind turbine, which can be used to validate the platform concepts for the next generation of wind turbines. Increasing the power of wind turbines leads to larger platforms due to the ne...
Article
Full-text available
Experts responsible for the safety evaluation of unique masonry heritage structures usually need to weigh information from various diagnosis activities before deciding the best course of action for preservation. Typical sources of valuable information are historical and in situ surveys and inspections, minor and non-destructive testing, structural...
Chapter
The increase of toughness and residual strengths are the great benefits of incorporating fibres in concrete. However, there is still no agreement regarding the most suitable experimental procedure for its determination and the most accepted and used tests, the bending tests, are complex to execute, require of sophisticated equipment with closed loo...
Article
Full-text available
Different brick masonry typologies have been and are still widely used in construction worldwide. Despite being a fundamental deformation property, experimentally determining the static elastic modulus in compression for brick masonry constituents remains a challenging task. Static modulus estimates usually show much larger dispersion than those in...
Article
Full-text available
Masonry heritage structures are often affected by slow irreversible deterioration mechanisms that can jeopardise structural stability in the foreseeable future. Static structural health monitoring (SHM), aimed at the continuous measurement of key slow‐varying parameters, has the potential to identify such mechanisms at a very early stage. This can...
Article
In recent years in Chile, the use of fiber reinforced shotcrete (FRS) has been widely extended in underground works, particularly in tunnels for roads, mines and hydroelectric projects. In these projects, the design of the supports is mainly based on the modified Q–Barton method, which relates the rock mass quality to the minimum energy absorption...
Article
Full-text available
The main objective of the Offshore Code Comparison Collaboration Continuation, with Correlation (OC5) project is validation of aero-hydro-servo-elastic simulation tools for offshore wind turbines (OWTs) through comparison of simulated results to the response data of physical systems. Phase III of the OC5 project validates OWT models against the mea...
Conference Paper
Full-text available
Static structural health monitoring (SHM), aimed at the continuous measurement of slow-varying parameters over a long period, has been proved to be a powerful tool to support the diagnosis of masonry heritage structures. In such applications, the initial interpretation task involves the identification of evolutionary conditions from recorded data....
Article
The mooring loading of floating offshore wind turbines are mainly induced by the platform motions through the fairleads. The dynamic analysis usually only considers the hydrodynamic forces over the mooring by the motion of the line disregarding the wave loads. Using the FloaWDyn aero-servo-hydro-elastic model, the influence of the wave hydrodynamic...
Article
Full-text available
Floating substructures for offshore wind turbines is a promising solution in order to harness the vast wind potential of deep water sites where bottom-fixed turbines are not feasible. The electrical system of large scale floating offshore wind farms will experience the application of new technologies and installation procedures that likely affect t...
Article
Efficient and accurate modelling of mooring and cable systems for Floating Offshore Wind Turbines are a key factor in the coupled dynamic analysis for the realistic assessment of such floating structures. In order to improve the modelling of the mooring and cable systems, a new extension of the slender rod finite element model proposed by Garret wi...
Conference Paper
Full-text available
The main objective of the Offshore Code Comparison Collaboration Continuation, with Correlation (OC5) project is validation of aero-hydro-servo-elastic simulation tools for offshore wind turbines (OWTs) through comparison of simulated results to the response data of physical systems. Phase III of the OC5 project validates OWT models against the mea...
Article
Fiber reinforced shotcrete (FRS) is widely used for tunnel construction. However, the systematic control of FRS properties is hampered by the complexities of the experimental procedures used. The experiments are normally based on the load-deflection response obtained from flexural tests with third-point loading performed under displacement control....
Article
Full-text available
When subjected to dynamic loading, materials can exhibit a mechanical behaviour quite different from its static counterpart. The evaluation of dynamic properties is thus very useful in the assessment of existing masonry structures. This paper presents results of an experimental campaign to determine both the dynamic Young's modulus and the shear mo...
Article
In this paper, a sensitivity analysis is performed on the levelized cost of energy (LCOE) for floating offshore wind farms (FOWFs). The analysis is carried out for three floating wind turbine concepts and three different offshore sites. At first, a methodology is presented for calculating the LCOE for a specific FOWF. Afterwards, the base LCOE valu...
Article
Floating offshore wind turbines (FOWT) have been extensively proven in model tests and are reaching currently a pre-commercial phase where large scale demonstrators are being built offshore. This transition increases the need for models able to assess the performance at suitable offshore locations. A simplified model is proposed that computes the d...
Article
Full-text available
The monolithic nature of Windcrete, that sees floater, transition piece and tower as a single concrete structure, has direct impact on its potential construction process. The large-draft spar-buoy, to be fully completed in a coastal facility, requires horizontal transport that prompts construction also to be done horizontally. Then, the constraints...
Article
The use of fiber reinforced concretes (FRC) as a substitute for reinforcement meshes, particularly in the construction of tunnels, frequently faces quality control problems because the specifications and acceptability criteria are based on parameters obtained from the flexion test of standard EN-14651, which is very difficult to perform at works. C...
Conference Paper
Full-text available
The main objective of the Offshore Code Comparison Collaboration Continuation, with Correlation (OC5) project, is validation of aero-hydro-servo-elastic simulation tools for offshore wind turbines (OWTs) through comparison of simulated results to the response data of physical systems. Phase III of the OC5 project analyzes the Senvion 5M wind turbin...
Conference Paper
Most numerical models for the analysis of offshore wind platforms are based on one of two different approaches, depending on how waves forces are applied to the structure: 1) the potential flow theory, and 2) the Morison equation. Potential flow theory allows to compute the wave forces more accurately when diffraction is relevant. Otherwise, this k...
Conference Paper
Las propiedades mecánicas del hormigón reforzado con fibras acero (HRFA) están íntimamente ligadas a la cuantía, tipología y orientación de las fibras. Determinar de manera fiable la resistencia a tracción del HRFA es un tema aún no resuelto y que está siendo investigado a nivel internacional. La tomografía mediante rayos X se ha erigido como una d...
Conference Paper
Durante los últimos años, en muchos proyectos que se ejecutan en Chile, para el control de calidad de los hormigones proyectados reforzados con fibras usados para el sostenimiento de túneles se utiliza la capacidad de absorción de energía, determinada con el ensayo de panel EFNARC. Sin embargo, este ensayo requiere muestras relativamente grandes y...
Article
Full-text available
This paper presents a simplified model for the dynamic analysis of a floating off-shore wind turbine (FOWT), which can be suitable for early feasibility and pre-engineering studies, where the complete system has to modeled in order to predict its behavior and to assess the performance. The model solves the equation of motion in time domain and cons...
Article
Full-text available
This paper summarizes the findings from Phase II of the Offshore Code Comparison, Collaboration, Continued, with Correlation project. The project is run under the International Energy Agency Wind Research Task 30, and is focused on validating the tools used for modeling offshore wind systems through the comparison of simulated responses of select s...
Article
Full-text available
The relevance of the interaction between the structural stiffness and the wind turbine dynamics are well known by the industry from decades of expertise. However, the novel floating concepts are commonly designed by tools that disregard the individual structural stiffness of the elements which compose the floating platform. Usually, these elements...
Article
Full-text available
In many tunnelling projects currently under construction in Chile, the quality of fiber reinforced shotcretes (FRS) is controlled by means of its energy absorption capacity determined by testing squared panel following the EFNARC recommendation. Nevertheless, this test requires large and heavy specimens, which have to be filled when concrete is spr...
Article
A description of the deformations and damage that occurred in a segmental tunnel lining as a consequence of an unplanned surface load is presented, as well as the numerical analyses performed for its safety assessment. The tunnel in study is located in soft soil conditions and presents a low overburden. Few months after tunnel drilling, a new bridg...
Article
Significant research efforts are now being directed at floating offshore wind turbines. The main challenge posed by floating wind turbines is the high construction and installation costs of the substructure, which make it too expensive for commercial exploitation in the current energy market. With the aim of achieving a cost-effective floating plat...
Article
Full-text available
A masonry pillar composed of solid clay bricks, cement mortar and infill is extracted from a historical structure and tested in concentric compression. It is subjected to cyclic and monotonic loads up to compressive failure.In parallel, samples are extracted from the pillar and are subjected to destructive tests. Non-destructive tests are performed...
Article
Full-text available
Tunnel construction commonly causes deformations of the surrounding ground, which can endanger buildings and other structures located in the vicinity of the tunnel. The prediction of these deformations and damages to buildings is difficult, due to limited knowledge of geotechnical conditions and due to uncertainty in predicting the response of the...
Article
This paper presents research results regarding the distribution of steel fibers in concrete used to build precast tunnel segments for Line 9 of the Barcelona Metro. The fiber distribution was studied using the actual fiber contents obtained by means of crushed cores drilled from different points of three full-scale tunnel lining segments. A statist...
Article
Full-text available
To estimate the economic feasibility of floating and bottom-fixed substructures at various offshore sites, a generally applicable calculation tool has been developed. With this “LCOE calculation tool” it is possible to optimize the design and reduce the costs of deep offshore wind farms, by analyzing key aspects already during the planning and pre-...
Article
Full-text available
One of the main aspects when testing floating offshore platforms is the scaled mooring system, particularly with the increased depths where such platforms are intended. The paper proposes the use of truncated mooring systems to emulate the real mooring system by solving an optimization problem. This approach could be an interesting option when the...
Article
Full-text available
A model for the analysis of masonry periodic unit cells of several wall and pillar geometrical typologies is proposed. It is based on a micro-mechanical analysis of the masonry cell, which has been divided into cuboids, and coupled with constitutive laws modeling the behavior of the materials in tension and multiaxial compression. The model may be...
Article
Tunnel excavation entails the generation of ground settlements, which can endanger the adjacent buildings. The prediction of damages is usually performed with the equivalent beam method from Burland and Wroth in 2D by assuming perpendicular buildings to the tunnel axis and Gaussian settlement profiles generated in their base. However, approximation...
Article
Tunnel construction entails the generation of ground settlements, which can endanger the adjacent buildings. The prediction of damages in buildings is usually based on the classical Gaussian profiles for the approximation of the subsidence trough and the equivalent beam method for modeling the response of building walls. Current available expressio...
Article
Segmental tunnel linings present a significant 3D response when they are subjected to localized loads or to other scenarios that produce different deformations of adjacent rings. The present paper analyzes the interaction mechanisms mobilized in such conditions, determining the most influence parameters and their repercussion on the structural resp...
Article
Full-text available
An experimental campaign involving the compressive testing of a brick masonry pillar extracted from a historical building is presented in this paper. The test procedure and the instrumentation are designed in order to determine, in addition to the compressive strength and global Young’s modulus of the structure, the behavior in different parts of t...
Conference Paper
Nowadays the offshore wind energy market is clearly oriented to be extended around the world. Bottom fixed solutions for supporting offshore wind turbines are useful in shallow waters which are available in a limited extent unless a continental shelf exists. Considering the Oil & Gas background knowledge, move from bottom fixed solutions to floatin...
Article
Full-text available
The paper focuses on the numerical prediction of the compressive response of masonry by means of detailed micro-modeling techniques. In such a model, the material constituents (mortar and units) and the unit-mortar interfaces are separately described by means of specific constitutive equations. The available modeling choices are evaluated through a...
Article
Full-text available
One of the main advantages of the Barcelona test is that the properties of fiber-reinforced concrete (FRC) can be determined by using cylindrical specimens, thereby permitting the use of cores to control the quality of concrete used in construction. Using the results of an extensive experimental campaign, this paper establishes the relationship bet...
Article
The current key challenge in the floating offshore wind turbine industry and research is on designing economic floating systems that can compete with fixed-bottom offshore turbines in terms of levelized cost of energy. The preliminary platform design, as well as early experimental design assessments, are critical elements in the overall design proc...
Article
Full-text available
The procedure and findings of an experimental campaign for the mechanical characterization of brick masonry with lime mortar joints are presented. The campaign includes the determination of the properties of the constituent materials and of the resulting masonry composite. The masonry consisted of masonry stack bond prisms made of solid clay bricks...
Article
A new concept of a SPAR floating platform is being developed in the KIC-Innoenergy project AFOSP (Alternative Floating Platform Designs for Offshore Wind Turbines using Low Cost Materials). Members of the consortium are Gas Natural Fenosa, University of Stuttgart and Universitat Politècnica de Catalunya. The main differentiating aspects with respec...
Book
Full-text available
RESUMEN El presente trabajo describe los resultados de una investigación experimental sobre el comportamiento de especímenes de concreto reforzado con fibras de acero utilizando el ensayo de doble punzonamiento (DPT, por sus siglas en inglés). El DPT es un ensayo de tracción indirecta basado en la configuración de ensayo de doble punzonamiento, lla...
Book
Full-text available
El presente trabajo describe los resultados de una investigación experimental sobre el comportamiento de especímenes de concreto reforzado con fibras de acero utilizando el ensayo de doble punzonamiento (DPT, por sus siglas en inglés). El DPT es un ensayo de tracción indirecta basado en la configuración de ensayo de doble punzonamiento, llamado ens...
Article
This paper analyzes, both experimentally and numerically, the effect of thermal curing on the evolution of temperatures, rate of temperature rise and cooling, stresses and strengths in reinforced concrete elements. It also describes the experimental program carried out to characterize thermally and mechanically the high strength concrete used in th...
Conference Paper
Full-text available
Tunnel construction can cause deformations of the surrounding ground, which endanger buildings and other structures located in the vicinity of the tunnel. The prediction of these deformations and the damages to the buildings is difficult due to limited knowledge of the geotechnical conditions and uncertainty in the response of the structures to the...
Article
The generalized Barcelona test proved to be adequate to characterize and control the fiber reinforced concretes (FRC) properties, providing results with a lower scatter than those obtained from other tests widely used to characterize properties of these concretes. This paper shows the results of an experimental program where this test is used to ch...
Article
This article presents the results of research carried out in the field of the structural response of tunnel linings made of precast concrete segments. The investigation began with the realization of a load test on a site located within an experimental section line 9 of the Barcelona Metro. The conclusions drawn about its behavior allowed the develo...
Article
Full-text available
Tradicionalmente, para caracterizar el comportamiento del concreto reforzado con fibra (CRF) se realizan ensayos a flexión en vigas. Sin embargo, de acuerdo con diferentes estudios sobre CRF, se ha observado coeficientes de variación del orden de 20 % para resultados de ensayo a flexión en vigas. Recientemente, se desarrolló un nuevo método basado...
Article
Full-text available
Traditionally, to characterize the behavior of reinforced concrete with fiber (CRF) flexural tests are performed on beams. However, in accordance with various studies on CRF, it has been seen different variation coefficients of the order of 20 % for the results of flexural test beams. Recently, it has been developed a new method based on the double...