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Wilmer Segundo Velilla Díaz

Académico - Profesor Asociado

Universidad de La Serena

La Serena, Chile

Líneas de Investigación


Mechanical behavior of Materials, Computational Mechanics, Nanomechanics, Data Analytics, Control Strategies

Educación

  •  Doctor Ingeniería Mecánica, Universidad del Norte. Colombia, 2019
  •  Magíster en Ingeniería Mecánica, Universidad del Norte. Colombia, 2008
  •  Ingeniero Mecánico, Universidad del Norte. Colombia, 2006

Experiencia Académica

  •   Académico - Profesor Asistente Full Time

    UNIVERSIDAD AUSTRAL DE CHILE

    Ciencias de la Ingeniería

    Valdivia, Chile

    2022 - 2024

  •   Académico - Profesor Titular Full Time

    Universidad Autónoma del Caribe

    Ingenierías

    Barranquilla, Colombia

    2009 - 2022

  •   Académico - Profesor Asociado Full Time

    UNIVERSIDAD DE LA SERENA

    Facultad de Ingeniería

    La Serena, Chile

    2024 - A la fecha

Experiencia Profesional

  •   Jefe dpto de diseño e ingeniería Full Time

    Comercializadora ICER de la Costa

    Barranquilla, Colombia

    2007 - 2008


 

Article (12)

Metallic foams have emerged as promising materials for mitigating the adverse effects of implants on surrounding tissues by replicating the stiffness and structural symmetry of bone. In current fabrication technologies, porosity is widely recognized as the primary topological factor for tuning stiffness and strength. However, as an isotropic parameter, porosity inadequately captures the influence of mesoscale structures on the elastic anisotropy of metallic foams. This study aims to address these limitations by investigating the role of porosity as a topological descriptor in determining elastic constants for anisotropic metallic foams. The research presents a methodology for determining the effective macroscopic elastic constants of orthotropic, titanium-based metal foams across varying porosities, ranging from 5% to 65%, which aligns with the pore size distributions of specimens fabricated via powder metallurgy. Employing genetic algorithm optimization based on Voronoi tessellations, 3D randomized cubic representative volume elements (RVEs) were generated to replicate pore statistics obtained from 2D mu CT reconstructions of real foams. Finite element simulations were conducted on these RVEs, including tensile and shear tests, to quantify their mechanical response. Results reveal a general reduction in Young's modulus, shear modulus, and bulk modulus as porosity increases. Notably, elastic constant dispersion significantly widened at higher porosity levels, with Poisson's ratio displaying substantial variation in the range of -0.01 < nu < 0.37 at 65% porosity. Zener ratios indicated near-isotropic behavior up to 30% porosity, but microstructural stability sharply declined beyond 65%, as reflected by nearly zero determinants of the stiffness tensors. These findings underscore the critical sensitivity of elastic properties, particularly Poisson's ratios, to microstructural architecture, providing insights into potential instabilities in highly porous, bone-like cellular structures.

Gomez, Ignacio Gonzalez; Lorca, Yerko Espinosa; Velilla-Diaz, Wilmer; Pacheco-Sanjuan, Alejandro

Article ISI
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES  (2025)

The continuous advancement of Laser Powder Bed Fusion (PBF-LB) has expanded the possibilities of additive manufacturing, particularly in producing complex geometries. A distinctive feature of the PBF-LB process is its capacity to develop crystalline patterns, which can be utilized to predict strength-enhancing orientations of the produced components. This work presents a unified methodology and models for evaluating the feasibility of leveraging these crystalline patterns, alongside material parameters and manufacturing conditions, to predict orientations that enhance the mechanical strength of PBF-LB components. By integrating manufacturing considerations early in the mechanical design process, this framework enables the optimization of component performance through the alignment of stress fields with favorable crystalline orientations. Experimental validation through microstructural characterization and tensile testing in samples manufactured under various orientations and PBF-LB parameters demonstrated that the predicted directions for maximum and minimum mechanical strength accurately corresponded to the evaluated conditions. Notably, the < 111 > directions exhibited superior mechanical strength compared to the isotropic material state. This study paves the way for improving mechanical performance and broadening the market potential of PBF-LB, emphasizing its applicability across diverse industries and component types.

Perez-Ruiz, Jose David; de Lacalle, Luis Norberto Lopez; Velilla-Diaz, Wilmer; Mesa, Jaime A.; Gomez, Gaizka; Maury, Heriberto; Urbikain, Gorka; Gonzalez, Haizea

Article ISI
MATERIALS & DESIGN  (2025)

Advanced Control Strategies for Cleaner Energy Conversion in Biomass Gasification

Barrios, Johann Monroy; Villegas, Jonathan Fabregas

Article ISI
SUSTAINABILITY  (2024)

Fatigue Life Estimation Model of Repaired Components with the Expanded Stop-Hole Technique

Guillen-Rujano, Renny; Perez-Ruiz, Jose David; de Lacalle, Luis Norberto Lopez; Maury, Heriberto

Article ISI
METALS  (2024)

Fired Heaters Optimization by Estimating Real-Time Combustion Products Using Numerical Methods

Palencia-Diaz, Argemiro; Fabregas-Villegas, Jonathan

Article ISI
ENERGIES  (2024)

Shear Stress Solutions for Curved Beams: A Structural Analysis Approach

Hernandez-Perez, Adrian

Article ISI
MATERIALS  (2024)

Effect of the grain boundary on the fatigue crack growth for aluminum bi-crystals

Velilla-Diaz, Wilmer; Zambrano, Habib R.

Article SCOPUS
Procedia Structural Integrity  (2023)

Effects of Grain Boundary Misorientation Angle on the Mechanical Behavior of Al Bicrystals

Velilla-Diaz, Wilmer; Zambrano, Habib R.

Article ISI
NANOMATERIALS  (2023)

Fuzzy gain scheduling: comparison of the control strategy



Article SCOPUS
JOURNAL OF ENGINEERING SCIENCE AND TECHNOLOGY  (2022)

Crack Length Effect on the Fracture Behavior of Single-Crystals and Bi-Crystals of Aluminum



Article ISI
NANOMATERIALS  (2021)

Fracture Toughness Estimation of Single-Crystal Aluminum at Nanoscale

Ricardo, Luis; Palencia, Argemiro

Article ISI
NANOMATERIALS  (2021)

The role of the grain boundary in the fracture toughness of aluminum bicrystal

Velilla-Díaz W.

Article ISI SCOPUS
COMPUTATIONAL MATERIALS SCIENCE  (2019)

1
Alejandro Pacheco

ACADÉMICO JORNADA COMPLETA

Ingeniería Mecánica

UNIVERSIDAD TECNICA FEDERICO SANTA MARIA

Valparaiso, Chile

1
Victor Palma

Profesor Auxiliar

Instituto de Ciencias Navales y Marítimas

Universidad Austral de Chile

Valdivia, Chile

12
Wilmer Velilla

Académico - Profesor Asociado

Departamento de Ingeniería Mecánica

Universidad de La Serena

La Serena, Chile

2
Renny Guillen

Académico

Instituto de Diseño y Métodos Industriasles

Universidad Austral de Chile

Valdivia, Chile