Stefan-Dan Pastrama

Prof. Dr. Stefan-Dan Pastrama

orcid

Research Focus & Metrics

Academic Career Length

29Years (1998-Present)

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

Representative Publications

View All Publications
1 January 2007 in Materials & Design (1980-2015)
Verified
Journal Article
Closed access
PMPedro Moreira
Pedro Moreira
PMP.F.P. de Matos
P.F.P. de Matos
PCPedro Ponces Camanho
Pedro Ponces Camanho
SPStefan-Dan Pastrama
Stefan-Dan Pastrama
Paulo M. S. T. de CastroPaulo M. S. T. de Castro
Paulo M. S. T. de Castro

30 September 2009 in Engineering Fracture Mechanics
Verified
Journal Article
Closed access
PMPedro Moreira
Pedro Moreira
SPStefan-Dan Pastrama
Stefan-Dan Pastrama
Paulo M. S. T. de CastroPaulo M. S. T. de Castro
Paulo M. S. T. de Castro

1 March 1998 in International Journal of Pressure Vessels and Piping
Verified
Journal Article
Closed access
SPStefan-Dan Pastrama
Stefan-Dan Pastrama
Paulo M. S. T. de CastroPaulo M. S. T. de Castro
Paulo M. S. T. de Castro

1 November 2010 in International Journal of Structural Integrity
Verified
Journal Article
Closed access
VRValentin Richter-Trummer
Valentin Richter-Trummer
PMPedro Moreira
Pedro Moreira
SPStefan-Dan Pastrama
Stefan-Dan Pastrama
Mário VazMário Vaz
Mário Vaz
Paulo M. S. T. de CastroPaulo M. S. T. de Castro
Paulo M. S. T. de Castro
Purpose: The purpose of this paper is to develop a methodology for in situ stress intensity factor (SIF) determination that can be used for the analysis of cracked structures. The technique is based on digital image correlation (DIC) combined with an overdetermined algorithm.Design/methodology/approach: The linear overdeterministic algorithm for calculating the SIF based on stress values around the crack tip is applied to a strain field obtained by DIC.Findings: As long as the image quality is sufficiently high, a good accuracy can be obtained for the measured SIF. The crack tip can be automatically detected based on the same strain field. The use of the strain field instead of the displacement field, eliminates problems related to the rigid body motion of the analysed structure.Practical implications: In future works, based on the applied techniques, the SIF of complex cracked plane stress structures can be accurately determined in real engineering applications.Originality/value: The paper demonstrates application of known techniques, refined for other applications, also the use of stress field for SIF overdeterministic calculations.

19 July 2023 in Aerospace
Verified
Journal Article
Open access
PDF file
AHAnton HADAR
Anton HADAR
AVAndrei Daniel Voicu
Andrei Daniel Voicu
BFBaciu Florin
Baciu Florin
VDVlasceanu Daniel
Vlasceanu Daniel
DTDaniela-Ioana Tudose
Daniela-Ioana Tudose
SPStefan-Dan Pastrama
Stefan-Dan Pastrama
This paper describes the transition towards a composite structure, with the same overall aerodynamic characteristics, for a tail rotor blade of an IAR330 helicopter. The newly proposed structure of the composite blade is made of a carbon-roving spar embedded with epoxy resin, a hexagonal-cell honeycomb core manufactured by fused deposition modelling, and an outer skin made of multiple carbon-fibre-reinforced laminae. The blade was manufactured by the authors using the hand lay-up method at a scale of 1:3 with respect to the real one, and all stages of the manufacturing process are extensively described in the paper. The experimental tests were performed on an Instron 8872 testing machine by applying a bending force on its free edge, similar to the testing methodology employed by various composite blade manufacturers. A three-dimensional numerical model of the tail rotor blade was conceived, analysed using the finite element method, and validated by comparing the numerical and experimental values of the maximum bending force. Further, the model was used for a complex finite element analysis that showed the very good behaviour of the proposed composite blade during flight and emphasized the main advantages brought by the proposed composite structure.

1 January 2008
Verified
Journal Article
Closed access
NINicolae Iliescu
Nicolae Iliescu
SPStefan-Dan Pastrama
Stefan-Dan Pastrama
LGLucian Gruionu
Lucian Gruionu
GJGabriel Jiga
Gabriel Jiga