J.A. Loya

Universidad Carlos III de Madrid

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Trends

Author Order

Document Type

Co-Authors

J. Fernández-Sáez

Universidad Carlos III de Madrid

Marcos Rodríguez-Millán

Universidad Carlos III de Madrid

J. Aranda-Ruiz

Universidad Carlos III de Madrid

María Henar Miguélez

Universidad Carlos III de Madrid

Ignacio Rubio

Universidad Carlos III de Madrid

R. Zaera

Universidad Carlos III de Madrid

Carlos Santiuste

Universidad Carlos III de Madrid

J. N. Reddy

Texas A&M University

A. Olmedo

Universidad Carlos III de Madrid

L. Rubio

Universidad Carlos III de Madrid

Cooperative Institutions

Universidad Carlos III de Madrid

Universidad Politécnica de Madrid

IMDEA Materials

Airbus (Spain)

Guardia Civil

Madrid Institute for Advanced Studies

San Diego State University

Universitat Politècnica de València

Instituto de Estudos Avançados da Universidade de São Paulo

Universidad de Zaragoza

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Field

Axisymmetric free vibration of closed thin spherical nano-shell

Composite Structures (2013)

R. Zaera J. Fernández-Sáez J.A. Loya

Elasticity

Spherical shell

Natural frequency

10.1016/j.compstruct.2013.04.022

Cite

Citations (29)

Energy absorption analysis of aramid composite during blunt projectile impact

Mechanics of Advanced Materials and Structures (2021)

I. Rubio Díaz Marcos Rodríguez-Millán A. Rusinek María Henar Miguélez J.A. Loya

In this work, a numerical model for aramid composites is experimentally validated in terms of permanent deformation, energy absorption and damage mechanisms for ballistic applications. Novel experimental and numerical results of non-perforating ballistic impacts with blunt projectiles are presented. The resistance forces and absorption energy by the specimen are measured for different impact velocities. A postmortem analysis of the failure mechanisms is performed using computed tomography and a profilometer device. The numerical model is used to analyze the influence of impactor mass and impact velocity below the ballistic limit.

Ballistic limit

Aramid

Ballistic Impact

Ballistics

Impact

10.1080/15376494.2021.1963020

Cite

Citations (13)

Ballistic Behavior of Fiber Composites

Ignacio Rubio J. Aranda-Ruiz Marcos Rodríguez-Millán J.A. Loya M.M. Moure

This chapter focuses on the analysis of fiber composite materials subjected to ballistic impacts. The study consists of both experimental and numerical analysis in aramid composite plates, characterizing their impact behavior in terms of their ballistic curve, and the different failure mechanisms that appear along the perforation process. The experimental setup includes a pneumatic gas gun, a high-speed camera, and two different projectiles: fragment simulating projectile (FSP) and metallic spheres. The maximum impact velocities reached is approximately 800 m/s. Additionally, a numerical model has been developed with the finite elements commercial code Abaqus/Explicit. The behavior of the material has been implemented by a VUMAT user subroutine. The numerical model has been calibrated and validated, reproducing faithfully the behavior of the material in terms of residual velocities, ballistic limit, and failure modes. It has been reported that the highest back-face displacement (BFD) occurs at velocities close to the ballistic boundary, leading to higher energy absorption and higher delamination in the fiber composite.

Ballistic limit

Ballistic Impact

Delamination

Perforation

Ballistics

Aramid

10.1002/9783527824571.ch7

Cite

Citations (1)

Analysis of high-speed impact problems in the aircraft industry

Courses and lectures (2013)

A. Árias J. López-Puente J.A. Loya D. Varas R. Zaera

Haulage

Load factor

Cost reduction

Aviation fuel

10.1007/978-3-7091-1768-2_4

Cite

Citations (2)

General expressions for the stress intensity factor of a one-point bend beam

Engineering Fracture Mechanics (2006)

I. Villa J.A. Loya J. Fernández-Sáez

Pure bending

10.1016/j.engfracmech.2006.05.020

Cite

Citations (7)

Analysis of the Machinability of Carbon Fiber Composite Materials in Function of Tool Wear and Cutting Parameters Using the Artificial Neural Network Approach

Materials (2019)

Norberto Feito Ana Muñoz-Sánchez Antonio Díaz-Álvarez J.A. Loya

Local delamination is the most undesirable damage associated with drilling carbon fiber reinforced composite materials (CFRPs). This defect reduces the structural integrity of the material, which affects the residual strength of the assembled components. A positive correlation between delamination extension and thrust force during the drilling process is reported in literature. The abrasive effect of the carbon fibers modifies the geometry of the fresh tool, which increases the thrust force and, in consequence, the induced damage in the workpiece. Using a control system based on an artificial neural network (ANN), an analysis of the influence of the tool wear in the thrust force during the drilling of CFRP laminate to reduce the damage is developed. The spindle speed, feed rate, and drill point angle are also included as input parameters of the study. The training and testing of the ANN model are carried out with experimental drilling tests using uncoated carbide helicoidal tools. The data were trained using error-back propagation-training algorithm (EBPTA). The use of the neural network rapidly provides results of the thrust force evolution in function of the tool wear and cutting parameters. The obtained results can be used by the industry as a guide to control the impact of the wear of the tool in the quality of the finished workpiece.

Delamination

Machinability

10.3390/ma12172747

Cite

Citations (13)

Modeling of impact dynamics and application in public security education

Multidisciplinary Journal for Education Social and Technological Sciences (2016)

Marcos Rodríguez-Millán Miguel Marco J.A. Loya Fernando Moure María Henar Miguélez

This work presents a methodology for interfacing with the students in order to study impact problems. The results are derived from the Bachelor Thesis developed at the end of the fourth course in the Security Engineering Degree. The knowledge regarding security topic and the use of new analysis tools (commercial finite element solver) have proved to be extremely useful for future Guardia Civil officers.

Interfacing

Bachelor

Solver

Dynamics

10.4995/muse.2016.3693

Cite

Citations (0)

Postmortem Analysis Using Different Sensors and Technologies on Aramid Composites Samples after Ballistic Impact

Sensors (2020)

Ignacio Rubio Antonio Díaz-Álvarez R. Bernier A. Rusinek J.A. Loya

This work focuses on the combination of two complementary non-destructive techniques to analyse the final deformation and internal damage induced in aramid composite plates subjected to ballistic impact. The first analysis device, a 3D scanner, allows digitalising the surface of the tested specimen. Comparing with the initial geometry, the permanent residual deformation (PBFD) can be obtained according to the impact characteristics. This is a significant parameter in armours and shielding design. The second inspection technique is based on computed tomography (CT). It allows analysing the internal state of the impacted sample, being able to detect possible delamination and fibre failure through the specimen thickness. The proposed methodology has been validated with two projectile geometries at different impact velocities, being the reaction force history on the specimen determined with piezoelectric sensors. Different loading states and induced damages were observed according to the projectile type and impact velocity. In order to validate the use of the 3D scanner, a correlation between impact velocity and damage induced in terms of permanent back face deformation has been realised for both projectiles studied. In addition, a comparison of the results obtained through this measurement method and those obtained in similar works, has been performed in the same range of impact energy. The results showed that CT is needed to analyse the internal damage of the aramid sample; however, this is a highly expensive and time-consuming method. The use of 3D scanner and piezoelectric sensors is perfectly complementary with CT and could be relevant to develop numerical models or design armours.

Aramid

Delamination

Ballistic Impact

Ballistic limit

Impact

10.3390/s20102853

Cite

Citations (17)

Bending of Euler–Bernoulli beams using Eringen’s integral formulation: A paradox resolved

International Journal of Engineering Science (2015)

J. Fernández-Sáez R. Zaera J.A. Loya J. N. Reddy

The Eringen nonlocal theory of elasticity formulated in differential form has been widely used to address problems in which size effect cannot be disregarded in micro- and nano-structured solids and nano-structures. However, this formulation shows some inconsistencies that are not completely understood. In this paper we formulate the problem of the static bending of Euler–Bernoulli beams using the Eringen integral constitutive equation. It is shown that, in general, the Eringen model in differential form is not equivalent to the Eringen model in integral form, and a general method to solve the problem rigorously in integral form is proposed. Beams with different boundary and load conditions are analyzed and the results are compared with those derived from the differential approach showing that they are different in general. With this integral formulation, the paradox that appears when solving the cantilever beam with the differential form of the Eringen model (increase in stiffness with the nonlocal parameter) is solved, which is one of the main contributions of the present work.

Virtual work

Differential form

Elasticity

10.1016/j.ijengsci.2015.10.013

Cite

Citations (393)

An Experimental and Numerical Study on the Influence of Helices of Screw Piles Positions on Their Bearing Capacity in Sandy Soils

Materials (2024)

Stanislav Simonenko J.A. Loya Marcos Rodríguez-Millán

Helical piles became a popular foundation technique, and as a result of environmental restrictions, they have become increasingly widely used. However, due to the high cost of experimentation, the influence of the number of helices and their positions on the pile-bearing capacity has not been sufficiently studied. The present study performed compression and lateral load tests on helical piles of the same diameter but with one, two, and three round helices in known sandy soil. The results from the experiments are compared with those from numerical simulations that use the mesh-free RBF method and the Winkler–Fuss approach to model how the pile and ground interact. The results are generalized to suggest an engineering equation that can predict the best pile configuration in sandy soil.

Foundation (evidence)

10.3390/ma17020525

Cite

Citations (2)