Article
Materials Science, Multidisciplinary
Zilong Zhao, Peng Zhang, Shengzhi Li, Jie Zhang, Weidong Shi, Chuangju Zhang, Yefei Li, Jingbo Yan, Fang Yang, Chang Zhang
Summary: The fatigue-creep properties of Ni-Fe based superalloy under different conditions vary significantly, showing that increasing strain amplitude, temperature, and holding time all have an impact on fatigue cycles. Dislocations bypass second phase particles during deformation, and longer holding time leads to the growth of the second phase, ultimately exceeding the critical size for dislocation cutting.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2021)
Article
Engineering, Civil
Mohammad Amin Farmani, Amin Heidarpour, Xiao-Ling Zhao
Summary: This study investigates the thermal creep of ASTM Grade 304 (EN 1.4301) austenitic stainless steel plate material when subjected to continuously rising temperatures. By experiment and analysis, an analytical creep model is developed that can simulate creep under transient conditions. The model is implemented in ABAQUS finite element software to simulate transient creep in a typical plate structural component. The study shows that transient creep effects have a significant impact on the buckling and failure temperatures of stainless steel plates.
THIN-WALLED STRUCTURES
(2022)
Article
Nanoscience & Nanotechnology
Yafei Li, Weijian Chen, Chuanyang Lu, Huaxin Li, Wenjian Zheng, Yinghe Ma, Ying Jin, Weiya Jin, Zengliang Gao, Jianguo Yang, Yanming He
Summary: This study investigated the effect of microstructural evolution on the creep behavior and deformation mechanism of the AlCoCrFeNi2.1 high-entropy alloys. The results showed that precipitation behavior was responsible for the accelerated creep and reduced creep life at high temperatures. The study also revealed differences in creep deformation mechanism and fracture behavior at different temperatures.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Review
Engineering, Mechanical
Marcello A. Lepore, Angelo R. Maligno, Filippo Berto
Summary: This study employed finite element modeling to simulate creep-fatigue crack propagation in Compact Tension C(T) specimens made of P91 steel at high temperatures, successfully comparing numerical and experimental results, and proposing a general methodology for simulation.
ENGINEERING FAILURE ANALYSIS
(2021)
Article
Engineering, Mechanical
Fernando J. Alamos, Martin Philo, David B. Go, Steven R. Schmid
Summary: This study simulated the contact between a single asperity/rigid tool under constant pressure using finite element modeling and design of experiments, and derived a new contact area expression based on characteristic time of asperity deformation.
TRIBOLOGY INTERNATIONAL
(2021)
Article
Engineering, Civil
Mohammad Amin Farmani, Amin Heidarpour, Clive Woo
Summary: This paper investigates the behavior of an innovative steel column section, composed of ultra-high strength steel tubes and stainless steel plates, under both room temperature and transient heating conditions of building fires. The vulnerability to local buckling is assessed through compressive tests, and appropriate plate width is determined. Transient fire tests are conducted with different heating rates to assess the effect of thermal creep on the fire resistance. Finite element (FE) models are verified using the fire tests, and a parametric study is performed to analyze the effects of length, utilization factor, axial restraint stiffness ratio, and heating rate on the fire resistance of the hybrid columns. Simplified design equations in the temperature domain are obtained based on the parametric study.
THIN-WALLED STRUCTURES
(2023)
Article
Nanoscience & Nanotechnology
M. Zhang, J. C. Gibeling
Summary: The stress reduction creep tests on a Cu-Cr-Nb alloy at 923 K revealed local dislocation climb as the rate-controlling deformation mechanism, with an activation energy consistent with self-diffusion in the Cu matrix. An internal back stress of approximately -9 MPa was found to act on the rate-controlling dislocations, believed to be the sum of interaction between dislocations and particles, as well as dislocations themselves. However, this back stress does not lead to a true threshold in thermally activated dislocation motion.
SCRIPTA MATERIALIA
(2021)
Article
Engineering, Mechanical
Fernando J. Alamos, Martin Philo, David B. Go, Steven R. Schmid
Summary: A pressing concern in superplastic forming (SPF) is the ability to quantitatively model to effectively design tooling and assess process viability. Current finite element method simulations for SPF generally do not include the evolutionary nature of friction under creep conditions. In this study, a new microcontact model of a rough surface in contact with a rigid flat surface is created to predict asperity flattening under creep behavior. Additionally, a semi-empirical equation is established to predict the real contact area and friction at different SPF conditions.
TRIBOLOGY INTERNATIONAL
(2022)
Article
Materials Science, Multidisciplinary
Z. Dong, L. Chen, Z. D. Xiang
Summary: A new grade of 11 wt% Cr steel was designed without nitrogen to minimize the formation of Z-phase and maximize the stability of MX precipitate particles. 6 wt% Co was added to suppress the formation of delta-ferrite in the matrix. The long-term creep rupture strengths of this new steel were higher than those of the strongest commercial 9-12 wt% Cr steel, P92 Steel.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2022)
Article
Engineering, Manufacturing
Richard J. Williams, Jalal Al-Lami, Paul A. Hooper, Minh-Son Pham, Catrin M. Davies
Summary: 316L stainless steel has been widely used in high temperature applications, and there are opportunities to utilize additive manufacturing in such applications. The creep behavior of LPBF 316L under multiaxial stress conditions was quantified, showing anisotropic creep response with faster minimum creep rates and shorter rupture lives in samples loaded perpendicular to the build direction. The columnar grain structure alignment with the build direction was attributed to this behavior.
ADDITIVE MANUFACTURING
(2021)
Article
Materials Science, Multidisciplinary
C. G. Shang, M. L. Wang, Z. C. Zhou, K. Yagi, Y. H. Lu
Summary: In this study, uniaxial creep tests were conducted on P92 steel at 650 degrees C under different applied stresses. The microstructure evolution and its effect on the corresponding creep behaviors were investigated. It was found that different stress levels resulted in different creep behaviors due to the evolution of hierarchical martensite structure and precipitates, as well as their interaction with dislocations.
MATERIALS CHARACTERIZATION
(2023)
Article
Biochemistry & Molecular Biology
Pawel Gumulka, Monika Tarsa, Monika Dabrowska, Malgorzata Starek
Summary: Grapiprant is a new analgesic and anti-inflammatory drug approved for the treatment of pain and inflammation associated with osteoarthritis in dogs. It acts as a selective antagonist of the EP4 receptor and has shown anti-inflammatory effects. This study presents the development of a method for the identification and quantification of grapiprant using thin-layer chromatography, and validates the method's reliability and sensitivity.
Article
Materials Science, Paper & Wood
Andi Hermawan, Hiroki Sakagami, Noboru Fujimoto
Summary: This study investigated the creep behavior of Japanese cypress boxed-heart timber at different temperatures, revealing that the creep behavior is temperature-dependent and creep compliances tend to increase with higher temperatures. The results successfully measured the viscoelastic and mechanosorptive creep parameters of the timber, showing good agreement with the models used in the study.
WOOD MATERIAL SCIENCE & ENGINEERING
(2022)
Article
Engineering, Mechanical
Le Xu, Lei He, Takaki Kojima, Takashi Nozawa, Takamoto Itoh
Summary: In this study, the deformation behaviors of F82H steel at 823 K under uniaxial and non-proportional loading conditions were described using a unified viscoplasticity model. The multiaxial creep-fatigue life was predicted using a strain energy damage parameter in collaboration with cycle-by-cycle concept. Our findings showed that the cyclic deformation behaviors were well described using the unified viscoplasticity model. The creep-fatigue life was well predicted by the proposed energy-based model within a factor of 2.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Materials Science, Multidisciplinary
C. G. Shang, M. L. Wang, Z. C. Zhou, Y. H. Lu
Summary: In this study, creep tests were conducted on 9Cr3W3Co steel at 650°C under 155-220 MPa in air and water vapor environments. The results showed that water vapor did not affect the creep deformation mechanism, but influenced the creep behaviors and life depending on the stress level. High stress levels in water vapor resulted in a decrease in steady-creep rate and an increase in steady-creep stage time, while low stress levels led to an increase in steady-state creep rate and a decrease in the time of steady-state creep stage. The interaction of different stresses and creep environments induced different forms of creep damage, affecting the creep fracture process and creep life.
MATERIALS CHARACTERIZATION
(2023)
Article
Chemistry, Multidisciplinary
Kristina Zgodavova, Peter Bober, Andrea Sutoova, Kristina Lengyelova
PRZEMYSL CHEMICZNY
(2019)
Article
Materials Science, Multidisciplinary
Maria Mihalikova, Kristina Zgodavova, Peter Bober, Andrea Sutoova
Article
Green & Sustainable Science & Technology
Kristina Zgodavova, Peter Bober, Vidosav Majstorovic, Katarina Monkova, Gilberto Santos, Darina Juhaszova
Article
Chemistry, Physical
Maria Mihalikova, Kristina Zgodavova, Peter Bober, Anna Spegarova
Summary: The research focused on the static and dynamic behavior of car body components welded from dissimilar steel sheets, investigating the influence of laser welding on mechanical and dynamical properties. Results showed that the strain rate had an impact on the mechanical properties of base materials and welded joints, with dynamic loading increasing yield stress more than ultimate tensile strength.
Article
Green & Sustainable Science & Technology
Gilberto Santos, Jose Carlos Sa, Maria Joao Felix, Luis Barreto, Filipe Carvalho, Manuel Doiro, Kristina Zgodavova, Miladin Stefanovic
Summary: The digitalization trend is sweeping the world, driving the transformation of industrial policies and quality management practices. Professionals in quality management need to possess creative thinking, leadership skills, communication abilities, teamwork capabilities, and understanding of Information and Communications Technology to thrive in the Industry 4.0 era.
Article
Chemistry, Physical
Kristina Zgodavova, Kristina Lengyelova, Peter Bober, Jose Alberto Eguren, Amaia Moreno
Summary: The research on 3D printing of protective face shields was motivated by the urgent societal demand for healthcare during the COVID-19 pandemic. The study compared three different filaments and ultimately chose PHA material for printing shield frames due to its superior environmental sustainability.
Article
Green & Sustainable Science & Technology
Sergio Carqueijo, Delfina Ramos, Joaquim Goncalves, Sandro Carvalho, Federica Murmura, Laura Bravi, Manuel Doiro, Gilberto Santos, Kristina Zgodavova
Summary: The development of Fab Labs was conceived in 2006 by Neil Gershenfeld from MIT, signaling a new era that integrates the digital and physical world. This study analyzes Portuguese Fab Labs and compares them to those in other European countries and the USA. The results show that Portuguese Fab Labs are still in an early stage with few users, although they have similar investment capacity and work areas as other European countries. The study suggests that to improve, Portuguese Fab Labs need better publicity, support for volunteers, a shift towards additive manufacturing, improved product quality and safety, and recognition of successful ideas.
Article
Chemistry, Multidisciplinary
Kristina Zgodavova, Peter Bober, Natasa Urbancikova, Gilberto Santos, Andrea Sutoova
Summary: This paper aims to model and predict the Level of Excellence of Slovak service organizations using the Gompertz logistic function and the EFQM excellence model. The study finds that the Gompertz function can accurately model the evolution of Excellence, but the original EFQM model has reached its limit in improving the overall effectiveness of service organizations in the country.
APPLIED SCIENCES-BASEL
(2022)
Article
Materials Science, Multidisciplinary
Jozef Petrik, Peter Blasko, Ivan Petryshynets, Maria Mihalikova, Alena Pribulova, Peter Futas
Summary: This study investigates the relationship between the degree of cold plastic deformation and the parameters of the Indentation Size Effect (ISE), as well as the influence of load and deformation degree on hardness and ISE parameters.
Proceedings Paper
Business
Kristina Zgodavova, Kristina Lengyelova, Peter Bober, Tibor Vincze
Summary: This chapter presents the history and application of role-play simulation (RPS) in the design of an integrated management system, and reports the survey results of using IMS-RPS to enhance an existing course. The study utilized target group discussions conducted through online interviews during the Covid-19 pandemic. The objective of the discussions was to improve the curriculum of the quality management system master course at the Technical University of Kosice (TUKE). The results of testing a new approach to education using innovative RPS virtual environment, smart glasses, and WebEx team collaboration tool with Verbal Feedback method contributed to learning, knowledge creation, and knowledge transfer. The study's limitations include the complexity of the organizational environment and the difficulty in measuring real improvement and validating the results empirically.
QUALITY INNOVATION AND SUSTAINABILITY, ICQIS 2022
(2023)
Proceedings Paper
Construction & Building Technology
Maria Mihalikova, Anna Spegarova, Jozef Petrik, Matej Babic
4TH INTERNATIONAL SCIENTIFIC CONFERENCE STRUCTURAL AND PHYSICAL ASPECTS OF CONSTRUCTION ENGINEERING (SPACE 2019)
(2020)
Article
Metallurgy & Metallurgical Engineering
Jozef Petrik, Peter Blasko, Maria Mihalikova, Andrea Vasilnakova, Vojtech Miklos
METALLURGICAL RESEARCH & TECHNOLOGY
(2019)
Proceedings Paper
Engineering, Manufacturing
Kristina Zgodavova, Andrea Sutoova, Miroslav Cicka
PROCEEDINGS OF THE 4TH INTERNATIONAL CONFERENCE ON THE INDUSTRY 4.0 MODEL FOR ADVANCED MANUFACTURING (AMP 2019)
(2019)
