<abstract xmlns="http://www.w3.org/1999/xhtml">

The main purpose of this article is to give an overview on the research conducted in the area of “supplier relationship management” in the industrial engineering field. To this overview, three main areas will be addressed. First, the evolution of the “supplier relationship management” function from being a technical knowledge broker across a business unit or organisation, to acting as a facilitator for the business’ strategic decision which need to be taken primarily within the supply chain management area. Second, how to set up a supply chain management governance system and what to consider for this system, in order to optimize the relevant activities and provide the expected supplier qualitative results. And finally, review on a set of tools and techniques for the supplier relationship management area, which, if implemented and used accordingly, can generate both short- and long-term benefits for its impacted stakeholders.
</abstract>

Analysis of the Supplier Relationship Management Function and Activities

<abstract xmlns="http://www.w3.org/1999/xhtml">

Living hinges are non-assemblable flexible joints that allow the relative rotation of two adjacent rigid parts through bending. Conventionally, living hinges are single-material designs made through injection moulding, for example. In order to reduce mould complexity, flexure hinges have a restrictive design. However, 3D printing technologies, such as Fused Filament Fabrication - FFF, can provide new opportunities for hinge development, allowing more design freedom and a wide range of materials. This paper focused on exploring and testing various multi-material hinges designs with bidirectional folding made of compatible and low-compatible thermoplastic materials. The resulting designs have corrugated structures and shape-changing interfaces, each with multiple solutions. They were printed as samples made of acrylonitrile butadiene styrene (ABS) and polylactic acid (PLA) for the rigid bodies and with thermoplastic co-polyesters (TPC) for the hinge. The results show that corrugated and shapechanging structures can be used as a design solution for flexure hinges.
</abstract>

“Gheorghe Asachi” Technical University of Iași

Department of Machine Manufacturing Technology

Ansbach University of Applied Sciences, Faculty of Technology

Design and Testing of Multi-Material Shape-Changing Flexure Hinges for Fused Filament Fabrication

<abstract xmlns="http://www.w3.org/1999/xhtml">

The technical evolution of the prosthetic field is swift and the technical solutions for the limb prostheses are found in a vast number of the specialized literature, therefore for good information management, a generalized classification of the field is necessary. Based on the use of the idea diagram method, a multicriteria classification of the lower and upper limb prostheses was performed. The classification was made according to the levels of limb amputation, the way of attaching prosthetic devices to the patient, the generations of technological performance adopted over time, the areas in which these prosthetic devices are used, and the mechanisms used for generation and transmission of forces in the joints of ankle &amp; foot prostheses. The results include general information and help novice researchers in future approaches to the field of limb prostheses.
</abstract>

dimitrie-cristian.fodor@student.tuiasi.ro

Technical Progress in Limb Prostheses: A Classification of Existing Devices

<abstract xmlns="http://www.w3.org/1999/xhtml">

Technologies such additive manufacturing are slowly becoming more and more present on the market, covering different areas of the industry due to its great potential. Even so, there are still many aspects which are unexplored or which can be improved. One of them being the study of the tribological proprieties for all these parts, which are produced through additive manufacturing methods, such as powder bed fusion, binder jetting, direct energy deposition, fused filament fabrication, material jetting, vat photopolymerization, and sheet lamination. The scope of this paper is to bring together the tribological proprieties for the 3D printed parts, and to have a critical analysis of these proprieties, in order to easily decide which printing method is suitable, depending of the working conditions of the printed component. In addition, this paper will describe the working principle for each technology, and the type of materials that are commonly used in the printing process. Depending of the printing method, the tribological proprieties vary greatly. For example, for the parts which are manufactured through powder bed fusion, it was found that the wear resistance is higher, and with a lower friction coefficient than for a part manufactured through traditional methods. In addition, for many printing methods, the produced part might require an additional step of treatment. This is the case with binder jetting, where infiltration and sintering are often used because the 3D-printed part is porous and weak. Some researchers found that the average friction coefficient measured for a steel-based part, treated with bronze infiltration, is comparable with the friction coefficient measured on a part made of the same material, manufactured through the direct energy deposition method. Of course, due to the physical limitations of the 3D printing method, the system will allow only the usage of a specific type or class of materials. One of such method is fused filament fabrication, where only thermoplastics are used. Along with vat photopolymerization and material jetting, these methods present comparable tribological proprieties.
</abstract>

A Review on Tribological Behaviour of 3D Printed Mechanical Components

<abstract xmlns="http://www.w3.org/1999/xhtml">

This paper focuses on a topic frequently involved in the dynamics of transient phenomena on rotary machines driven by an AC induction motor supplied by a three-phase four-wire electrical system: the free response of the dynamic system mirrored in the torsional vibrations of its rotor. This dynamic system is reducible at a single degree of freedom system, equivalent of a spring-mass-damper but as a torsional vibratory system composed of the motor rotor (having a moment of inertia) the rotating magnetic field (having a torsional stiffness) and a hypothetical damper (generating a viscous damping mainly due to the air friction). This free response is useful mostly to characterize the transmissibility related to the conversion of information from mechanical to electrical power through this dynamic system. A simple computer-assisted setup is used to describe indirectly and to analyze the free response (generated when the motor is switched-on or after star to delta commutation sequence), using the active electrical power absorbed by the motor.
</abstract>

A Study on the Dynamics of an AC Induction Motor Rotor Based on the Analysis of Free Response at Impulse Excitation

<abstract xmlns="http://www.w3.org/1999/xhtml">

Nowadays quality management and specific tools can represent a challenge in SMEs (small and medium enterprises). To assure the expected quality of the products, SPC (statistical process control) combined with industry 4.0 specifics offer instantaneous responses and triggers for needed actions. Therefore, risk analyses are used as enablers for quality-oriented behaviour, and risk mitigation and identification, together with collected data, represent a comprehensive system that leads enterprises to achieve the expected performance level needed to remain competitive in the market. In addition, risk management and quality management cannot be treated without looking at the maintenance activities and policies which can have a considerable impact on those two. This paper provides a comprehensive literature review of the papers from the quality management sector and articles where risk management and maintenance are seen as facilitators for quality improvement with an impact on the performance level. The main contribution of each paper is listed in the table which simplifies the reader’s access to the work done in the field and the overview presented enables easy access to trends in this field and offers a starting point for future research by presenting the gaps.
</abstract>

Quality and Risk Management in Industrial Production Systems: A Literature Review

<abstract xmlns="http://www.w3.org/1999/xhtml">

Water Framework Directive defines the river longitudinal continuity as “undisturbed migration of aquatic organisms and sediment transport”. Electrical energy production from hydro sources is the main risk that generates hydromorphological alteration of surface waters by disconnecting the rivers. The flow reduction on the river sector from the water intake to the restitution point of the small hydropower plant is also considered as a hydromorphological alteration that can modify the natural hydrological regime.
This paper presents good practices for ensuring the river longitudinal connectivity while Small Hydropower Plants are implemented. In order to restore the river longitudinal connectivity for fish migration, some types of fish passages used within the hydropower facilities from Europe are presented and discussed.
The recommended solutions are important to mitigate the small hydropower plants’ negative effects on river ecosystems and it can contribute to the increase of energy power units based on renewables.
</abstract>

“Gheorghe Asachi” Technical University of Iaşi

Restoring River Connectivity in Line with European Legislation

<abstract xmlns="http://www.w3.org/1999/xhtml">

The presented paper develops a practical maintenance procedure in the case of injectors, including the necessary steps. It is important to analyze the engine control parameters, the injection, the engine behavior in specific given conditions. By using the maintenance equipment to check the injectors that are electronically operated, we can observe certain variations of them, such as operating parameters, actual and nominal operating values. We performed the maintenance of the injectors, measuring the amount of diesel eliminated on the return, from here observing a disproportionality between the quantities. The accomplishment of this paper leads to an objective that highlights the problems related to the behavior of the supply system and implicitly, problems that can occur at the injectors that use the Common - Rail supply system.
</abstract>

Research on the Maintenance of Common-Rail Injectors

<abstract xmlns="http://www.w3.org/1999/xhtml">

Air cushion vehicles represent an interesting research area, mainly from their application point of view. But, at the same time, represents the reason of the scarcity of published results. Based on a series of initial simulations carried out by authors, which analysed lift forces for a round-shaped air cushion vehicle where the segments of the flexible skirt were inclined at 90˚, it was decided to carry out more complex studies regarding this configuration, presented in a series of articles. This complex study consists in performing static CFD simulations, in which values for different constructive elements are modified in order to analyse their influence on lift force. In this first article, the imposed fixed parameters are: angle of inclination of the segments of the flexible skirt and height of the segments, respectively. The main constructive variable parameters are: air clearance height and length between the edge of the bag to cushion feed orifice and inner wall of the flexible skirt segments. The simulations were carried out in ANSYS Fluent software, where velocity contours, streamlines and velocity profiles from the exit under the flexible skirt were analysed and through Curve Fitting Toolbox application found in MATLAB program, the equations were established that describe lift force variation.
</abstract>

CFD Analysis of a Round Shaped Air Cushion Vehicle with Flexible Skirt Segments at 90° Part I: Different Positions of Bag to Cushion Feed Orifice

<abstract xmlns="http://www.w3.org/1999/xhtml">

Based on the bond-graph model of a system dynamics, the differential equations that represent the mathematical model can be determined. In case of a system with storing energy elements in derivative causality and with more degrees of freedom, the computational effort is an important one. The present work proposes an easier method for finding the differential equations, based on the derivative of kinetic energy.
</abstract>

The Dynamic Equations of a Mechanical System Using the Bond-Graph Method and the Kinetic Energy

AHEAD OF PRINT

Volume 69 (2023): Issue 3 (September 2023)

Volume 69 (2023): Issue 2 (June 2023)

Volume 69 (2023): Issue 1 (March 2023)

Volume 68 (2022): Issue 4 (December 2022)

Volume 68 (2022): Issue 3 (September 2022)

Volume 68 (2022): Issue 2 (June 2022)

Volume 68 (2022): Issue 1 (March 2022)

Volume 67 (2021): Issue 4 (December 2021)

Volume 67 (2021): Issue 3 (September 2021)

Volume 67 (2021): Issue 2 (June 2021)

Volume 67 (2021): Issue 1 (March 2021)

Bulletin of the Polytechnic Institute of Iași. Machine constructions Section

 Machine Construction section, as part of the Bulletin of the Polytechnic Institute of Iasi founded in 1946, appears as an autonomous publication since 1950. Currently, it is issued in both printed and electronic format, on a quarterly basis, and is included in a library exchange program with 84 other publications. The Machine Construction section is a technical scientific journal which publishes original research papers, as well as occasional reviews of treaties, lectures and monographs in various fields of Mechanical Engineering. Main topics include: theoretical and applied machine mechanics; fluid mechanics and hydro-pneumatic machines; robotics; tribology; machine manufacturing; machining technologies; industrial management; economical engineering in mechanics; machine design; mechatronics; theoretical and experimental study of strain and stress; micromechanical systems; materials machinability and surface finishing technologies; machine tools; automotive; internal combustion engines; steam and gas turbo-engines; refrigeration machines and heat pumps; renewable energy sources; heat transfer; cogeneration and tri-generation systems; applied thermodynamics and thermal systems; combustion; agricultural mechanics and machinery; technologies and equipment for food processing and food industry; bioengineering and biofuels; traffic and safety etc. At this time, there is no publication fee and full-text papers are available open-access on the university website. The review process of each submitted paper includes an anti-plagiarism test with specialized software and a double-blind independent review. The authors are notified at each stage of the process. The rejection rate is above 50%. The main publication language is English.  Archiving  Sciendo archives the contents of this journal in Portico - digital long-term preservation service of scholarly books, journals and collections.  Plagiarism Policy  The editorial board is participating in a growing community of Similarity Check System's users in order to ensure that the content published is original and trustworthy. Similarity Check is a medium that allows for comprehensive manuscripts screening, aimed to eliminate plagiarism and provide a high standard and quality peer-review process. 