- TITLE:
INVESTIGATING THE EFFECT OF THE INFILL DENSITY AND GEOMETRY ON SOME MECHANICAL PROPERTIES OF PETG COMPONENTS MANUFACTURED USING FUSED FILAMENT FABRICATION
- AUTHOR(S):
N. Petrov
- ABSTRACT:
In this work the effect of the infill density and geometry on the tensile and flexural properties of polyethylene terephthalate glycol (PETG) samples prepared using fused filament fabrication (FFF) was investigated. The infill density was varied between 15 %, 25 %, and 35 %, and the samples were denoted as T1, T2, and T3, correspondingly. All samples exhibited similar tensile strength with the maximum one being 18.05 MPa of the 35 % infill density sample. The flexural strength of samples T1-T3 was nearly identical meaning the infill density did not have a major effect on it. Based on the performed mechanical tests, the highest infill density was chosen to prepare three more samples where the infill geometry was varied. Three infill geometries were used, namely a triangular one, a honeycomb one, and an octet one, with samples denoted at T4, T5, and T6, accordingly. The results indicated that the highest tensile force of 18.31 MPa was achieved by using a honeycomb infill pattern, however, the octet pattern sample exhibited the highest flexural strength of 32.40 MPa. Samples T5 and T6 also required the highest printing time and raw material input, thus increasing the material cost for production. However, the obtained results emphasize the importance of selecting an appropriate design for the desired application where an optimal choice between cost and functionality should be made.
- DOI:
https://doi.org/10.62853/LIVX2292
- PAGES:
41-48
- DOWNLOAD:
INVESTIGATING THE EFFECT OF THE INFILL DENSITY AND GEOMETRY ON SOME MECHANICAL PROPERTIES OF PETG COMPONENTS MANUFACTURED USING FUSED FILAMENT FABRICATION
- HOW TO CITE THIS ARTICLE:
Petrov N. INVESTIGATING THE EFFECT OF THE INFILL DENSITY AND GEOMETRY ON SOME MECHANICAL PROPERTIES OF PETG COMPONENTS MANUFACTURED USING FUSED FILAMENT FABRICATION. Journal of the technical university of Gabrovo. 70 (2025) 41-48. https://doi.org/10.62853/LIVX2292
- TITLE:
INFLUENCE OF DIAMOND BURNISHING GOVERNING FACTORS ON THE SURFACE MICROHARDNESS OF AUSTENITIC STAINLESS STEELS
- AUTHOR(S):
M. Ichkova
- ABSTRACT:
Diamond burnishing (DB) is an effective finishing that dramatically improves the performance of metal components due to the favorable combination of surface integrity characteristics. A comprehensive study of the effects of DB governing factors of AISI 304 steel specimens on the microhardness was conducted using an optimal second-order composition plan, ANOVA and regression analysis. Mathematical model of the surface microhardness depending on the burnishing force, feed rate and burnishing velocity was obtained. Based on the results obtained, it was found that the combination of high burnishing force, minimum feed rate and minimum burnishing velocity maximizes the surface microhardness.
- DOI:
https://doi.org/10.62853/WRDV8518
- PAGES:
35-40
- DOWNLOAD:
INFLUENCE OF DIAMOND BURNISHING GOVERNING FACTORS ON THE SURFACE MICROHARDNESS OF AUSTENITIC STAINLESS STEELS
- HOW TO CITE THIS ARTICLE:
Ichkova M., INFLUENCE OF DIAMOND BURNISHING GOVERNING FACTORS ON THE SURFACE MICROHARDNESS OF AUSTENITIC STAINLESS STEELS. Journal of the Technical university of Gabrovo. 70 (2025) 35-40. https://doi.org/10.62853/WRDV8518
- TITLE:
PENETRATION DEPTH IN LASER MARKING OF COMPOSITE MATERIALS WITH TEXTILE REINFORCEMENT PHASE
- AUTHOR(S):
Simeon Tsenkulovski
- ABSTRACT:
This publication investigates the influence of the technological parameters of the laser marking process on the penetration depth of the laser beam in composite materials based on phenolic laminate with a textile reinforcing phase. Studies was conducted at the output power of the laser radiation - P=5÷50 W, marking speed - V=50mm/s and pulse frequency - f=50Hz. A graphical dependence of the obtained experimental results in comparison with the theoretical values is presented.
- DOI:
https://doi.org/10.62853/AYZZ6684
- PAGES:
30-34
- DOWNLOAD:
PENETRATION DEPTH IN LASER MARKING OF COMPOSITE MATERIALS WITH TEXTILE REINFORCEMENT PHASE
- HOW TO CITE THIS ARTICLE:
Tsenkulovski S. PENETRATION DEPTH IN LASER MARKING OF COMPOSITE MATERIALS WITH TEXTILE REINFORCEMENT PHASE. Journal of the Technial university of Gabrovo. 70 (2025) 30-34. https://doi.org/10.62853/AYZZ6684
- TITLE:
PROCESS MANAGEMENT IN ENGINEERING PROJECT PLANNING
- AUTHOR(S):
Tsanka Zlateva-Petkova
- ABSTRACT:
The planning process group consists of those processes performed to establish the overall scope of the activity, define and refine objectives, and develop an action plan necessary to achieve those objectives. The planning processes build the engineering project management plan and documentation that will be used to implement it. The purpose of this report is to systematize and summarize the groups of processes necessary for the successful implementation of engineering projects, in order to make their implementation and adaptation easier in practice, which will significantly support the work of specialists in the planning and organization of engineering activities in industrial enterprises. The author makes no claims to exhaustiveness, as well as to the mandatory and literal application of the topic discussed in the practice of industrial processes. To achieve the goal, the methodology of system-structural analysis was used, which creates the opportunity to consider related processes and phenomena as a structured system that functions at the level of the industrial enterprise. One of the serious limitations that the author finds is that there is almost no research and there is a serious lack of scientific literature on the problems and issues related to project planning processes, and in particular, on planning engineering projects in industrial enterprises.
- DOI:
https://doi.org/10.62853/JYCD1949
- PAGES:
24-29
- DOWNLOAD:
PROCESS MANAGEMENT IN ENGINEERING PROJECT PLANNING
- HOW TO CITE THIS ARTICLE:
Zlateva-Petkova Ts. PROCESS MANAGEMENT IN ENGINEERING PROJECT PLANNING. Journal of the Technical university of Gabrovo. 70 (2025) 24-29. https://doi.org/10.62853/JYCD1949
- TITLE:
ENGINEERING PROJECTS FOR CONSTRUCTION OR RECONSTRUCTION OF INDUSTRIAL ENTERPRISES
- AUTHOR(S):
Tsanka Zlateva-Petkova
- ABSTRACT:
One of the important tasks of industrial design is the creation of engineering projects for the construction of new or reconstruction of existing industrial production processes and enterprises. The developed projects must meet certain conditions and a number of engineering and technical requirements in order to ensure high technical and economic indicators of the industrial enterprises. The aim of this paper is to specify some of the important characteristics of engineering projects for the industrial design of production processes and to propose a model for the technological design process, as this will systematize the steps and sequence in the process, as well as significantly facilitate any practitioner in this field. To achieve the goal, the comparative analysis method was used, comparing the types of possible engineering projects, on the basis of which the author developed the model proposed in the paper. The limitations in the study are reduced to the fact that the author himself sets the boundaries of his research and chooses only engineering projects, since project management is a vast scientific territory, and the volume of a scientific paper is too short. The topic is well known and still relevant because engineering project management is a daily activity for management specialists, but unfortunately there is still much to add and improve in the knowledge, skills and competencies of managers. Overall, the author believes that this is a topic that would help to achieve higher goals and results, and to improve the existing management practice.
- DOI:
https://doi.org/10.62853/QNHU8585
- PAGES:
18-23
- DOWNLOAD:
ENGINEERING PROJECTS FOR CONSTRUCTION OR RECONSTRUCTION OF INDUSTRIAL ENTERPRISES
- HOW TO CITE THIS ARTICLE:
Zlateva-Petkova Ts. ENGINEERING PROJECTS FOR CONSTRUCTION OR RECONSTRUCTION OF INDUSTRIAL ENTERPRISES. Journal of the Technical university of Gabrovo. 70 (2025) 18-23. https://doi.org/10.62853/QNHU8585
