Theory and Applications of Mathematics and Computer Science

Manufacturing Process of the SAV PALET Dacia Renault

Alexandru Puiu Barbos — Tue, 01 Sep 2026 00:00:00 +0300

The paper analyzes the technological workflow used to manufacture the welded SAV PALET G assembly intended for the
Renault/Dacia application, starting with the procurement of semi-finished materials and continuing with cutting, machining on
numerically controlled equipment, turning of the parts, welding, stress relieving, hot-dip galvanizing and final inspection. The
study uses technical data from the attached technological documentation and focuses on the engineering interpretation of the
manufacturing parameters. Calculations are presented for spindle speed, feed rate, theoretical machining time and an example
of dimensional verification. The results show that the sequence of operations must be established so that geometric accuracy,
welded-assembly stability and corrosion protection are maintained throughout the entire manufacturing cycle.

Mathematical Analysis and Structural Optimization of an Insulated Support for the 25 kv–50 hz Railway Contact Line

Alexandru Puiu Barbos — Tue, 01 Sep 2026 00:00:00 +0300

This paper presents a structural analysis of an insulated support assembly used in 25 kV–50 Hz railway overhead contact
lines. The study is based on the supplied engineering drawings of the stay rod, brace, direct steady arm, reverse fixing device,
bar, couplings, fixing plate and contact-wire clamp. The dimensions and materials explicitly readable in the drawings are incorporated
into a simplified analytical model for bending, shear and elastic displacement. The reference configuration mainly uses
S235/S235JR/FMN35 steels with corrosion protection by hot-dip galvanizing, while CuZn15 and other steels/stainless components
are present in the contact clamp and fasteners. AlCu4Mg is investigated as a lightweight alternative for selected structural members.
The analysis confirms the substantial mass-saving potential of aluminium alloys, but also the associated loss of sti ness;
therefore, a material substitution must be accompanied by geometric redesign. For the ?34 4 mm tubular direct steady arm, with
L = 400–1600 mm, the section properties are calculated and a conservative Fd = 90 N case is used to quantify the sensitivity of
bending moment and elastic displacement to length. The proposed methodology combines mass, strength and sti ness criteria and
can be extended by finite-element analysis.

Mathematical Modeling, Structural Resistance Calculation, and Technological Itinerary for Manufacturing the Y25 Bogie Frame

Paul Ilie Varsendan — Tue, 01 Sep 2026 00:00:00 +0300

This paper presents an analytical and mathematical approach to the dynamic stress phenomena acting on the supports and
protection devices of railway track inductors. The main objective of the research is the mathematical substantiation of the transition
from the use of conventional structural steels (S235J2) to superior alloys (S355J2) in railway infrastructure, through a rigorous
analysis of stress tensors and safety coecients. Based on equilibrium equations and bending models under transient shocks and
accelerations, it has been demonstrated that adopting the S355J2 material increases the structural safety coecient by over 50%,
ensuring the continuous operation of trac safety systems (PZB/Indusi).

Mathematical Analysis of Dynamic Stresses and Structural Optimization of Protection Devices for Railway Track Inductors

Paul Ilie Varsendan — Tue, 01 Sep 2026 00:00:00 +0300