|
Journal PROCEEDINGS IN MANUFACTURING SYSTEMS |
|
ISSN 2343–7472 ISSN-L 2067-9238 |
|
|
|
|
Journal PROCEEDINGS IN MANUFACTURING SYSTEMS □
Volume 18, Issue 4, 2023 · Ion BADEA, Diana
POPESCU, Tudor-George ALEXANDRU, Finite
element analysis in the study and optimization of external fixators · Cosmin GOGU,
Cristina PUPĂZĂ, George CONSTANTIN, Small
satellites and technology development. A review Using
software and mathematical methods to optimize logistics flows. A case study Finite element analysis in the study and
optimization of external fixators Ion BADEA1, Diana POPESCU2,*,
Tudor-George ALEXANDRU3 1) PhD Student, Dep. of Robots and Production Systems, National
University of Science and Technology POLITEHNICA Bucharest, Bucharest,
Romania 2) Prof., PhD, Dep. of Robots and Production Systems, National
University of Science and Technology POLITEHNICA Bucharest, Bucharest,
Romania 3) Lecturer, PhD, Dep. of Robots and Production Systems, National
University of Science and Technology POLITEHNICA Bucharest, Bucharest,
Romania Abstract: This paper reviews recent approaches using finite element analysis for
designing and optimizing orthopedic external fixators for stabilizing and
healing bone fractures. Key aspects include design methods, numerical
simulations, experimental and clinical validations. Furthermore, the
mechanical properties of the human bone are investigated. Studies have explored
various external fixator designs and configurations, by employing stress
analysis to understand the mechanical behavior of the external fixator-bone
construct, and optimizing the design and placement of frames, rods, and pins.
The primary goals are to reduce the fixator’s mass while maintaining
necessary external fixator-bone stiffness for stability and healing, as well
as to evaluate different configurations, and to provide data on optimal
external fixator removal timing. Focusing mainly on external fixators for
tibial fractures, the paper also includes insights from femur fracture
studies. Hybrid external fixators are less frequently studied compared to
linear or Ilizarov fixators. A notable aspect is the variability in external
fixator configurations, tailored to patient anatomy and fracture type.
Developing a comprehensive bone model is crucial, incorporating both cortical
and cancellous bone types, as well as cortical thickness, which respond
differently to stress due to varying material properties such as the Young’s
modulus and Poisson’s ratio. Additionally, stages of callus formation,
essential to bone healing, correspond to changes in the stiffness of the
fixator-bone system, load transfer capacity of the external fixator, and
interfragmentary strain values. Key words: external fixator, finite element analysis,
bone, mechanical properties, orthopedics, design, simulation, stiffness. Small satellites and technology development.
A review Cosmin GOGU1,*, Cristina PUPĂZĂ2,
George CONSTANTIN3 1) Ph.D. Student, Eng, Robots and Manufacturing System Department,
University Politehnica of Bucharest, Romania 2, 3) Prof., Ph.D., Eng, Robots and Manufacturing Systems Department,
University Politehnica of Bucharest, Romania Abstract: The paper's main objective is to present the current stage of development
in the aerospace field. A brief history of small satellites and the
classification of satellite sizes is presented. Research directions in the
aerospace field are presented as defined by the National Aeronautics and
Space Administration (NASA) and European Space Agency (ESA). An analysis of
the research directions is proposed for development for materials, design,
production and testing of spatial structures. Improvements in designing of
structures focuses on Modeling, Optimizations and Validation stages, with
recommendations for each stage. Small satellites development is accelerating
for nano-satellites class, which offers best cost-performance ratio, recent
developments are enabling bigger size Card Sat like 12U and 16U to be used in
upcoming missions. Key words: small satellites, development, design
methodology. Using
software and mathematical methods to optimise a bottling flow Constantin-Rareș DIACONU1,*,
Constantin-Adrian POPESCU2, Cicerone Laurențiu POPA3, Emilia-Maria POPESCU4, Costel Emil COTEȚ5 1) PhD, Robots and Production
Systems Dep., National University of Science and Technology POLITEHNICA
Bucharest, Romania 2) Lecturer, PhD, Robots and Production Systems Dep., National
University of Science and Technology POLITEHNICA Bucharest, Romania 3) Assoc. Prof., PhD, Robots and Production Systems Dep., National
University of Science and Technology POLITEHNICA Bucharest, Romania 4) Lecturer, PhD, Robots and Production Systems Dep., National
University of Science and Technology POLITEHNICA Bucharest, Romania 5) Prof., PhD, Robots and Production Systems Dep., National University
of Science and Technology POLITEHNICA Bucharest, Romania Abstract: Automating processes has emerged as a
significant global trend within the bottling industry, with a rising number
of companies now focusing on this aspect. The present study conducted a
simulation to optimise a bottling flow using the WITNESS Horizon software.
The main objective of increasing the profit was achieved by optimising the
bottling flow by modifying working times and implementing two new bottling
lines. In addition, another efficient method was presented, which was solved
using Kuhn's algorithm to optimise the proposed flow. The system designed in
the present study was compared to other systems in the bottling industry
market. The research found that the system proposed in this paper was the
most efficient as it could complete a whole cycle of bottling and packing ten
boxes in a shorter time than the other systems. Keywords: automation, bottling
flow, simulation,
algorithm, optimisation. |
||||||||||||||||
|
|
