Ali Hajjia

Dr. Ali Hajjia


Research Focus & Metrics

Academic Career Length

2Years (2025-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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13 February 2025 in Symmetry
Verified
Journal Article
Open access
PDF file
BEERADA-GOUZI MOHAMMEDBEERADA-GOUZI MOHAMMED
BEERADA-GOUZI MOHAMMED
AHAli Hajjia
Ali Hajjia
AEA. Elkhalfi
A. Elkhalfi
BHBilal Harras
Bilal Harras
Sorin VlaseSorin Vlase
Sorin Vlase
Maria Luminita ScutaruMaria Luminita Scutaru
Maria Luminita Scutaru
In the context of the automotive industry, this paper proposes an enhancement of the numerical simulation using FEM and performing material choosing with the Ashby method for automotive brake discs, using the symmetric shape of the disc. Automotive braking involves the dissipation of kinetic energy through heat generation due to friction, a physical phenomenon that alters the mechanical properties of brake discs. This prompts automotive development engineers to investigate new materials capable of absorbing heat while maintaining their mechanical properties. A thermomechanical study of a ventilated front brake disc has successfully demonstrated a good performance of cast iron because the equivalent stress is significantly lower than the elastic limit, with a margin of approximately 73 MPa. Compared to validated results extracted from the state of the art, the adopted methodology gives more realistic results with minimum CPU requirements, where the total time of calculation is around 40 min. More than that, the results are suitable to be used for studying durability and other properties like mechanical impact and fatigue.

13 February 2025 in Mathematics
Verified
Journal Article
Open access
PDF file
AHAli Hajjia
Ali Hajjia
SFSaid EL Fakkoussi
Said EL Fakkoussi
BHBilal Harras
Bilal Harras
AEA. Elkhalfi
A. Elkhalfi
Sorin VlaseSorin Vlase
Sorin Vlase
Maria Luminita ScutaruMaria Luminita Scutaru
Maria Luminita Scutaru
This paper explores and discusses how wing structures vibrate by using the Mindlin–Reissner plate theory, which takes into consideration the effects of transverse shear deformation and rotary inertia. This theory works well for thicker structures, like aircraft wings, where it gives accuracy by detecting shear and rotation effects. FGMs, or functionally graded materials, are used in aviation to enhance structural patterns and reduce stress points by gradually changing material properties along the wing thickness based on the volume fraction index. Finite element method (FEM) simulations were conducted to compare the natural frequencies and mode shapes of tapered and interpolated wing geometries. The results indicate that interpolated meshes exhibit higher natural frequencies due to increased stiffness, whereas tapered meshes show lower frequencies due to their flexibility. Validation through ANSYS simulations confirms the accuracy of the FEM results, highlighting the influence of geometry and material gradation on vibrational behavior. The findings offer valuable insights for aerospace applications, supporting the development of lightweight and efficient wing designs.