Profile URL: https://hdl.handle.net/20.500.13091/11619
Job Title:Doç. Dr.
Email Address:smdemet@ktun.edu.tr
Main Affiliation:02.10. Department of Mechanical Engineering
Status: Current Staff
ORCID:
0000-0002-9795-0939
0000-0002-9795-0939Scopus ID:
56635854700
56635854700YÖK Akademik: 0BF7A9249F82892E
Google Scholar:
cK4MFUAAAAAJ
cK4MFUAAAAAJWeb of Science ID:
OOM-2476-2025
OOM-2476-2025Name Variants:
Demet, S. Mehmet Demet, Seyit M.
16 results
Scholarly Output Search Results
Now showing 1 - 10 of 16
Article Citation - WoS: 7Citation - Scopus: 8An Analysis of the Effect of Pressure Angle Change on Bending Fatigue Performance in Asymmetrical Spur Gears(SAGE PUBLICATIONS LTD, 2021-06-28) Demet, Seyit Mehmet; Ersoyoğlu, Ali SerhatIn this study, the fatigue performances of symmetrical and asymmetrical spur gears were analyzed by performing single tooth bending fatigue tests. The gears tested were determined to be symmetrical spur gears with a 20 degrees/20 degrees pressure angle, asymmetrical spur gears with a 20 degrees/22 degrees pressure angle, and asymmetrical spur gears with a 20 degrees/25 degrees pressure angle. These gears were made of AISI 4140 material. Single tooth bending fatigue tests were performed under variable loads. Considering the tests performed at the same torque values in asymmetrical spur gears with a 20 degrees/22 degrees pressure angle compared to symmetrical spur gears with a 20 degrees/20 degrees pressure angle, a statistically significant increase in performance was achieved at close to 90%. While gears with 20 degrees/20 degrees and 20 degrees/22 degrees pressure angles break at the tooth root, tooth flank fracture was observed in relatively high numbers of cycles in asymmetric spur gears with a 20 degrees/25 degrees pressure angle. It was observed that the formation of tooth flank damage negatively affected the fatigue performance.Other Solid Particle Erosion Behaviors of Walnut Shell-Filled (Acrylic-Styrene-Acrylate) [ASA] and (Polycarbonate/Acrylic-Styrene-Acrylate) [PC/ASA] Thermoplastic Blend Biocomposites(2024) Karagöz, İdris; Sepetçioğlu, Harun; Demet, Seyit Mehmet; Bağcı, MehmetArticle Erosive Wear Behavior of FRP Composite Pipes Under Varying Impingement Angles, Impact Velocities and Flow Directions(Elsevier Sci Ltd, 2026-02-01) Demet, Seyit Mehmet; Kepir, Yusuf; Gunoz, Alper; Sepetcioglu, Harun; Bagci, Mehmet; Kara, MemduhFiber-reinforced polymer (FRP) composite pipes are emerging as superior alternatives in sectors such as oil and gas, chemical processing, and aerospace, owing to their high strength-to-weight ratio, corrosion resistance, and design flexibility; however, their long-term durability is susceptible to erosion wear when exposed to abrasive particles. This study experimentally investigates the solid particle erosion (SPE) behavior of filament-wound carbon (CFR/EP), glass (GFR/EP), and basalt (BFR/EP) fiber-reinforced epoxy pipes by ASTM G76-18. Tests were conducted under varied impingement angles (30 degrees, 45 degrees, 60 degrees, 90 degrees), flow directions (axial and radial), and particle velocities (28 and 34 m/s), using both erosion rate (ER) and volumetric material loss to assess performance. All composites demonstrated a semi-ductile erosion response, with degradation consistently peaking at a 45 degrees impingement angle across all test conditions. An increase in particle velocity from 28 to 34 m/s induced a near two-fold escalation in ER. Among the materials, BFR/EP exhibited the highest erosion rates, whereas CFR/ EP was the most resistant. Notably, ER values were consistently higher in the axial flow direction, exceeding radial values by 20-40 % under the most severe condition (45 degrees at 34 m/s). Paradoxically, despite its lower ER, CFR/EP suffered greater volumetric material loss than GFR/EP, a discrepancy attributed to its significantly lower fiber volume fraction (42.4 %) compared to GFR/EP (68.9 %) and BFR/EP (59.7 %). These findings emphasize that both ER and volumetric loss are critical metrics for designing thin-walled pipes, thereby providing a crucial scientific basis for material selection in environments characterized by erosive, multi-directional flow.Article Filament Sarım Bazalt / Epoksi Kompozit Boruların İç Yüzey Erozif Aşınma Davranışına Partikül Hızı ve Çarpma Açısının Etkisi(2022-12-30) Demet, Seyit Mehmet; Sepetçioğlu, Harun; Bağcı, MehmetKompozit malzemeler birçok alanda özellikle metal esaslı malzemelere alternatif olarak uygulama alanı bulmaktadır. Bu deneysel çalışmada Bazalt Elyaf Takviyeli Epoksi (BET/EP) kompozit boruların savunma sanayi, denizcilik, alt yapı ve aktarım tesislerinde kullanımı dikkate alınmıştır. Bu amaçla yüksek kimyevi ve ısıl denge, iyi mukavemet, sıcaklık/elektrik ve ses yalıtım özellikleri de gösteren Bazalt Elyaf Takviyesi (BET) tercih edilmiş olup Epoksi (EP) matris ilavesiyle CNC filament sarım makinelerinde [±55]4 sarım konfigürasyonunda kompozit borular ürettirilmiştir. Boru içerisinde partiküllü akışın olduğu uygulamaların temelinde farklı hızlara sahip aşındırıcıların boru içerisindeki akış yönü doğrultusunda farklı açılarda çarpması amaçlanmıştır.Boru içi katı partikül erozif aşınmayı araştırmak için, ASTM G76-95 standardıyla uyumlu deney setinde çift disk metodu kullanılarak belirlenen 23, 28, 34 ve 53 m/s çarpma hızlarındaki açısal geometriye sahip ~600 µm aşındırıcı partiküller, 30°, 45° ve 60° olmak üzere üç farklı çarpma açısında BET/EP kompozit boruların iç yüzeyine etki edecek şekilde tekrarlı deneyleri yapılmıştır ve sonuçlar yorumlanmıştır. Partiküllerin çarpma hızındaki artışın boru iç yüzeyinde erozyon direncini azalttığı sonucuna ulaşılmıştır. Kompozit boru iç yüzeyindeki aşınma davranışının yarı sünek malzemelerde oluşan erozyon aşınması modeli ile uyum sağladığı belirlenmiştir.Article Citation - WoS: 8Citation - Scopus: 9A Comprehensive Experimental Study of Enhanced Solid Particle Erosive Resistance on the Inner/Outer Surface of Graphene Nanoplatelets Modified Basalt/Epoxy Composite Pipe(Wiley, 2023-08-01) Sepetcioğlu, Harun; Demet, Seyit Mehmet; Bağcı, MehmetBasalt fiber reinforced polymer (BFRP) composite pipe is an excellent alternative to glass and carbon fiber reinforced composite pipes in industry and promising in high recycling for polymer composite used in aerospace, marine, and automo-tive. To enhance the solid particle erosion (SPE) properties of filament-wound BFRP composite pipe while preserving its mechanical properties, reinforced BFRP composite pipes were prepared to employ non-functionalized graphene nanoplatelets (GnPs) at a reinforcement concentration of 0.25 wt.% and ultra-sonication mixing technique. The SPE behavior of GnPs reinforced and non-reinforced BFRP composite pipes were characterized by axial and radial positioning of the inner and outer surfaces of the pipes. In each case, the ero-sion rates of these composite pipes were evaluated at five impingement angles (30 degrees, 45 degrees, 60 degrees, 75 degrees, and 90 degrees) and an impact velocity of 34 m/s. The erosion response of both BFRP composite pipes' outer surfaces showed a semi-ductile in the axial positioning, with a maximum erosion rate at a 60 degrees impingement angle. However, these composite pipes' inner surfaces in the same positioning presented a maximum erosion rate at a 45 degrees impingement angle. Besides, it is explored that the GnPs contribute to an improvement of approximately 10%-55% in erosive wear resistance of the non-reinforced BFRP composite pipes. The damage analysis of eroded surfaces was examined through scanning electron microscopy (SEM), and the GnPs effect upon composite pipes' erosion micro-mechanisms was presented and discussed in detail.Article Citation - WoS: 1Citation - Scopus: 1Influence of Temperature and Stress Ratio on Low-Cycle Fatigue Life Prediction of UD-CFRCs Considering Stiffness Degradation(Wiley, 2025) Demet, Seyit Mehmet; Demir, OkanThis study explores the feasibility of stress-based and residual-strength-based methodologies for fatigue life prediction of unidirectional carbon fiber-reinforced composites (UD-CFRCs) under low-cycle fatigue (LCF) loading. The influence of temperature and stress ratio on stiffness degradation is also investigated. Stiffness degradation increased with increasing temperature, resulting in reduced fatigue life. Similarly, higher stress ratios accelerated stiffness degradation in the UD-CFRCs. However, increasing stress ratios also prolonged Stage II, the cumulative damage progression phase, consequently increasing fatigue life. To evaluate predictive capabilities, two distinct LCF failure models were employed: one based on the Basquin equation and the other on residual strength. These models were applied across three temperatures and four stress ratios, and their results compared. The Basquin equation-based model provided better agreement with experimental observations.Article Citation - WoS: 7Citation - Scopus: 7Solid Particle Erosion Behavior on the Outer Surface of Basalt/Epoxy Composite Pipes Produced by the Filament Winding Technique(MDPI, 2023) Demet, Seyit Mehmet; Sepetcioğlu, Harun; Bagci, MehmetBasalt/epoxy composite pipes in a [+/- 55](4) winding configuration were produced on CNC filament winding machines (10 N fiber tension and similar to 11 mm bandwidth). In the experiments, a 34 m/s impact velocity was set using the double-disc method, and five different particle impingement angles (30, 45, 60, 75, and 90 degrees) were used to determine the erosive effect on the outer surfaces of filament wound composite pipes under the influence of 600 mu m erodent particles with angular geometry in the test set, complying with the ASTM G76-95 standard. The winding patterns in the lamina (+/- 55 angle-ply laminate region) and zigzag (+/- 55 zigzag region) regions of BFR/EP pipes were determined to have significant effects on solid particle erosion resistance, as evidenced by the SEM images.Article Investigation of the Effect of Hardness on Gear Tooth Failure by Bending Fatigue Test(2022) Demet, Seyit Mehmet; Ersoyoğlu, Ali SerhatThis study investigated the effect of hardness change on the types of damage caused by fatigue damage at the symmetrical and asymmetrical gear teeth made of AISI 4140 material. In the experimental study, gear teeth were subjected to load by the Single Tooth Bending Fatigue (STBF) test method. The gear teeth were loaded with different torque values to examine the fatigue damage. Damages in symmetrical gears happened as a result of the progression of cracks in the tooth root region. In asymmetric gears, on the other hand, it has been observed that the way damage changes rely on the load, the number of cycles, and the hardness. In asymmetrical teeth, relatively high cycle numbers were reached in the tests performed with low torque. The tooth flank damage occurred as a result of crack growth in the teeth at relatively low loads and high cycles.Article Citation - WoS: 1Citation - Scopus: 1Synergistic and Antagonistic Effects of Hybridization and MWCNT Reinforcement on the Solid Particle Erosion of Glass/Carbon Fiber Composites(MDPI, 2025-09-09) Demet, Seyit MehmetA systematic investigation into the solid particle erosion (SPE) of monolithic, sandwich-type hybrid and multi-scale (Multi Wallet Carbon Nanotube (MWCNT)-reinforced) glass/carbon fiber composites was performed confirming to the ASTM G76-18 standard, utilizing angular alumina erodent (similar to 600 mu m) at 34 m/s across key impingement angles of 30 degrees, 45 degrees, 60 degrees, and 90 degrees. The analysis reveals a profound performance dichotomy dictated by the governing wear mechanism. At the shear-dominated 30 degrees angle, where maximum material loss was observed, hybridization consistently enhanced erosion resistance relative to both monolithic benchmarks. This synergy, however, contrasts sharply with the nuanced behavior under the 90 degrees impact-dominant regime; here, although strategically hybridizing a brittle CFRP with tougher glass fibers reduced the erosion rate (ER) by a remarkable similar to 50%, this benefit was compromised by the matrix embrittlement induced by MWCNT incorporation. This work clarifies the difference between shear-dominated erosion in the ductile regime and fracture toughness under impact-dominated conditions.Other Effect of Graphene Nanoplatelets on Erosion Behavior of Basalt Fiber-Reinforced Polymer Composite Pipes Under High Temperatures(2025) Demirci, Musa; Sepetçioğlu, Harun; Demet, Seyit Mehmet; Bağcı, Mehmet
Research Topics
Domains
Physical Sciences
Fields
Environmental ScienceEngineeringMaterials Science
Subfields
Ecological ModelingMechanical EngineeringMaterials ChemistryOcean EngineeringMechanics of Materials
Specific Research Areas
Erosion and Abrasive Machining
Gear and Bearing Dynamics Analysis
High-Velocity Impact and Material Behavior
Particle Dynamics in Fluid Flows
Metal and Thin Film Mechanics
Sustainable Development Goals
9INDUSTRY, INNOVATION AND INFRASTRUCTURE
3
Research Products
Documents
11
Citations
38
h-index
4
Documents
10
Citations
67
Publication Collaboration
| Affiliation Name | Count |
|---|---|
| Konya Technical University | 12 |
| Selçuk University | 7 |
| Yalova University | 2 |
| KTO Karatay University | 1 |
| Mersin Üniversitesi | 1 |
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Data obtained from OpenAlex
| Journal | Count |
|---|---|
| Polymer Composites | 3 |
| Polymers | 2 |
| ECF22 - LOADING AND ENVIRONMENTAL EFFECTS ON STRUCTURAL INTEGRITY | 2 |
| PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART L-JOURNAL OF MATERIALS-DESIGN AND APPLICATIONS | 1 |
| Research Square | 1 |
Current Page: 1 / 3
Scholarly Output
16
Articles
11
Views / Downloads
39/98
Supervised MSc Theses
0
Supervised PhD Theses
1
WoS Citation Count
29
Scopus Citation Count
34
Patents
0
Projects
0
WoS Citations per Publication
1.81
Scopus Citations per Publication
2.13
Open Access Source
12
Supervised Theses
1
Scopus Quartile Distribution
Competency Cloud
