Article
Engineering, Mechanical
Keith Davey, Muhammed Atar, Hamed Sadeghi, Rooholamin Darvizeh
Summary: The new scaling theory introduces new similitude rules and extends the classical definition of similitude for nonlinear structural dynamics. Application of two properly designed scaled experiments can significantly extend the limited scope provided by a single scaled experiment, demonstrating benefits for a range of loading conditions. Exact similitude for two scaled experiments is confirmed, providing exact replication of behaviors over long timescales.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2021)
Article
Mechanics
Keith Davey, Osagie Akhigbe-Midu, Rooholamin Darvizeh, Hamed Sadeghi
Summary: The size effect in fatigue loading indicates that smaller components of the same material have increased fatigue resistance. This study explores the possibility of establishing an analytical relationship between fatigue life and scale, and shows that using two scaled-down experiments can accurately capture the complete fatigue response of a structure.
ENGINEERING FRACTURE MECHANICS
(2023)
Article
Engineering, Civil
Lilin Zhou
Summary: The study proposes a new similitude method to correct the distortion caused by the non-scalability of ply thickness in laminated composite cylinders, aiming to establish high-precision similitude of their free vibration. The method is verified through numerical examples and shown to solve the similitude distortion with high accuracy, applicable to various cylinders with different ply thickness, stacking sequences, and materials.
THIN-WALLED STRUCTURES
(2021)
Article
Engineering, Mechanical
Keith Davey, Rooholamin Darvizeh, Muhammed Atar, Ali Golbaf
Summary: Scaled experimentation is an important approach for investigating complex systems, but traditional methods such as dimensional analysis do not address scale effects. A new theory based on finite similitude and space scaling offers a more comprehensive understanding of scale dependencies and allows for alternative scale-invariances. This new approach requires two scaled experiments at different scales to achieve a more accurate representation of behaviors in complex systems.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2021)
Article
Engineering, Environmental
Riikka Matala, Mikko Suominen
Summary: Climate warming poses higher requirements for sustainability in the ship industry, leading to stricter power restrictions and the development of new ship hull designs. However, current model scale testing principles for predicting vessel's ice performance are suboptimal, especially for vessels operating in old, frequently used brash ice channels. This paper introduces a new similitude number - the Channel number - to more accurately predict ship resistance in brash ice conditions and enhance harmonization of ice performance with ice classes.
COLD REGIONS SCIENCE AND TECHNOLOGY
(2023)
Article
Engineering, Mechanical
Keith Davey, Hamed Sadeghi, Rooholamin Darvizeh, Ali Golbaf, Abolfazl Darvizeh
Summary: The finite similitude theory is a new scaling method that aims to capture scale effects by conducting two scaled experiments at different scales, providing a more realistic approach to scaled experimentation. By combining information from two experiments, the theory can predict outcomes that may be superior to experiments at a single scale.
INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
(2021)
Article
Engineering, Mechanical
Lei Li, Zhong Luo, Yuqi Li, Fengxia He, Xiang Li, Xiaolu Yan
Summary: This paper presents a method to obtain scaling laws for low-pressure compressors considering bolted joints. The results show that scaled models can accurately predict various dynamic characteristics.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART C-JOURNAL OF MECHANICAL ENGINEERING SCIENCE
(2022)
Article
Multidisciplinary Sciences
Keith Davey, Hamed Sadeghi, Rooholamin Darvizeh
Summary: Scaled experimentation is an important method, but it is limited by scale effects. This article introduces a new approach called finite similitude for electro-magnetic systems, which can address the scale dependencies and the limitations of traditional scaled experiments. The benefits of performing two scaled experiments are also discussed.
PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
(2022)
Article
Acoustics
Lei Li, Zhong Luo, Fengxia He, Kai Sun, Xiaolu Yan
Summary: This paper proposes a method for identifying the unbalance value of full-size rotor systems through scaling laws and scaled models. The effectiveness of the method is verified through numerical and experimental case studies, and the results show that the unbalance values can be accurately identified.
JOURNAL OF SOUND AND VIBRATION
(2022)
Article
Engineering, Mechanical
Osagie Akhigbe-Midu, Keith Davey, Rooholamin Darvizeh, Hamed Sadeghi
Summary: New similitude rules are explored in numerical experiments for industrially representative fatigue-crack growth scenarios, showing for the first time how geometric size effects in mixed mode fatigue tests can be eliminated through appropriately designed scaled experiments. The new rules accurately predict crack-path and have errors ranging from 1% to 9% in lifecycle predictions.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2023)
Article
Engineering, Civil
K. Davey, R. Darvizeh, M. Atar
Summary: The paper discusses the limitations of scaled experiments in earthquake-resistant structure design and introduces a new theory based on space scaling to address scale effects more effectively. Unlike traditional dimensional analysis, the finite similitude approach incorporates scale effects and links experiments at multiple scales to reconstruct full-scale behavior.
ENGINEERING STRUCTURES
(2021)
Article
Mechanics
Keith Davey, Rooholamin Darvizeh, Osagie Akhigbe-Midu, Hamed Sadeghi
Summary: This paper investigates the application and assessment of cohesive zone models in the design and analysis of scaled models. Considering the challenges with scale dependencies, a new scaling theory called finite similitude has been introduced. The results show that using the first-order finite similitude rule and applying two scaled experiments can reduce the discrepancies between scaled models and full-sized specimens.
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
(2022)
Article
Environmental Sciences
Shakil Ahmed, Omar Abdul-Aziz
Summary: We investigated the relationship and scaling property of dissolved oxygen (DO) in coastal streams along the U.S. Atlantic Coast. By employing dimensional analysis methodology, we discovered two meaningful dimensionless numbers, the stream 'metabolic' number and the fraction of 'DO saturation' number. Through graphical exploration, we found three different metabolic regimes and developed a generalized empirical model to successfully predict DO in diverse streams across the U.S. Atlantic Coast.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Chemistry, Physical
Hiroshi Nakatsuji, Hiroyuki Nakashima, Yusaku I. Kurokawa
Summary: This paper generalizes the scaling function g for accurate solutions of the Schrodinger equation with the free complement theory. The scaling functions for electron-nuclear and electron-electron interactions are generalized. The conditions for collisional and asymptotic behavior lead to the classification of scaling functions into correct, reasonable, and approximate classes. The accuracy of various electron-electron scaling functions is examined for the helium atom, with the functions produced from the potential operator showing higher importance. The correct-class scaling functions give the most accurate results, while the reasonable-class functions are less accurate.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Engineering, Mechanical
Sina Milani, Hormoz Marzbani, Nasser Lashgarian Azad, William Melek, Reza N. Jazar
Summary: Dimensional analysis plays a crucial role in engineering experimentation, especially for large-scale systems like aircraft and ships, making cost-effective and simplified experiments possible. While the automotive industry did not see the need for dimensional analysis in the past, the introduction of autonomous vehicles has changed the situation.
VEHICLE SYSTEM DYNAMICS
(2022)
Article
Materials Science, Characterization & Testing
Shanmugam Chinnuraj, Thyla Pudukarai Ramaswamy, Mohanram Pidugun Venkatachalam, Mahendrakumar Nataraj, Ramu Murugan, Mohanraj Selvakumar, Shanmugasundaram Dhandabani, K. N. ManojKumar
Summary: Stone-based polymer composite materials are being considered as alternate materials for machine tool structures due to their improved damping characteristics. The process parameters of epoxy granite composite were optimized to achieve optimum strength properties, with the recommended parameters showing significant improvements in damping and bonding characteristics.
JOURNAL OF TESTING AND EVALUATION
(2021)
Article
Engineering, Mechanical
T. Satish Kumar, S. Shalini, M. Ramu, Titus Thankachan
JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY
(2020)
Article
Materials Science, Multidisciplinary
Prabhu Raja Venugopal, P. Dhanabal, P. R. Thyla, S. Mohanraj, Mahendrakumar Nataraj, M. Ramu, Harshad Sonawane
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART L-JOURNAL OF MATERIALS-DESIGN AND APPLICATIONS
(2020)
Article
Engineering, Mechanical
Arunkumar Damodharan, Ramu Murugan, Syath Abuthakeer
Summary: The study experimentally explored the cooling performance of combined cooling systems, finding that using a hybrid ground-coupled heat exchanger can effectively reduce the energy consumption of traditional window air conditioners.
TRANSACTIONS OF THE CANADIAN SOCIETY FOR MECHANICAL ENGINEERING
(2021)
Article
Polymer Science
Lovin K. John, Ramu Murugan, Sarat Singamneni
Summary: The development of fused filament fabrication has expanded the application range of additive manufacturing in various research fields, but the mechanical strength of parts printed using this technology is lower due to anisotropic behavior and void formation. Studies have been conducted on the effect of design and process parameters on the mechanical properties, but the impact of build orientations and raster patterns needs further attention. The study aims to fabricate parts with quasi-isotropic laminate arrangement of rasters and compare their mechanical properties with traditional raster orientations, showing improved mechanical behavior in various tests.
HIGH PERFORMANCE POLYMERS
(2022)
Article
Engineering, Mechanical
K. Sripriyan, M. Ramu, P. R. Thyla, K. Anantharuban
Summary: A comprehensive numerical model was developed to predict the transient temperature distribution during gas metal arc welding process with flat wire electrode (FW-GMAW). The numerical analysis indicated that the peak temperature increased due to the increased heat power density in the flat wire electrode, affecting the geometry of the weld bead.
JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY
(2021)
Article
Engineering, Mechanical
C. Somu, R. Ranjith, P. K. Giridharan, M. Ramu
Summary: The requirement for processes with high productivity has driven the development of new tools and machining techniques, one of which is the development of a Copper Composite (CC) tool reinforced with graphite particles. By using different input variables and analyzing surface morphology, the best applications for different tool materials were identified based on Material Removal Rate (MRR), Tool Wear Ratio (TWR), and Surface Roughness (R-a).
SURFACE TOPOGRAPHY-METROLOGY AND PROPERTIES
(2021)
Article
Engineering, Mechanical
R. Ranjith, Manoj B. S. Prabhakar, P. K. Giridharan, M. Ramu
Summary: This research explores machining of Ti6Al4V titanium alloy using AA6061/10 Gr composite tool, achieving optimal performance through the addition of Al2O3 particles and optimization of parameters.
SURFACE TOPOGRAPHY-METROLOGY AND PROPERTIES
(2021)
Article
Engineering, Manufacturing
M. Jayashuriya, S. Gautam, A. Nithish Aravinth, G. Vasanth, Ramu Murugan
Summary: This research focuses on investigating the dimensional deviations in the Fused Deposition Modelling process using ABS material and optimizing 3D printing parameters. The study found that small-sized features have higher dimensional deviations and identified the significant impact of infill percentage and number of shells on the dimensional deviation of 3D printed ABS samples.
PROGRESS IN ADDITIVE MANUFACTURING
(2022)
Article
Engineering, Manufacturing
S. R. Amithesh, Balasurya Shanmugasundaram, Shravya Kamath, S. S. Adhithyan, Ramu Murugan
Summary: Fused Deposition Modeling (FDM) process is an economical 3D printing process, but it is prone to surface and dimensional defects. This study investigates the inaccuracies in the FDM process using appropriate artifacts and Coordinate Measuring Machine (CMM). A standard test artifact is designed to study curling and geometric form errors. Nine configurations of the artifact model are 3D printed using optimum process parameters. The artifact with the least accuracy is selected for further investigation. Taguchi's L9 Orthogonal Array is used for 3D printing the selected artifact. The geometric form errors of the 3D printed artifact are evaluated using CMM measurement, and the optimal process parameters are determined based on ANOVA test results.
PROGRESS IN ADDITIVE MANUFACTURING
(2023)
Proceedings Paper
Computer Science, Artificial Intelligence
N. Mahendrakumar, P. R. Thyla, P. Mohanram, M. Ramu, V. Prabhu Raja, C. Raja Kumaran, K. N. Manojkumar, A. Siddarth
ADVANCES IN SIMULATION, PRODUCT DESIGN AND DEVELOPMENT
(2020)
Proceedings Paper
Materials Science, Multidisciplinary
D. Arunkumar, M. Ramu, R. Murugan, S. Kannan, S. Arun, Sanjeevi Baskar
MATERIALS TODAY-PROCEEDINGS
(2020)
Proceedings Paper
Materials Science, Multidisciplinary
Varun S. Rajan, M. Govindaraju, M. Ramu, V Satheeshkumar
MATERIALS TODAY-PROCEEDINGS
(2020)
Article
Thermodynamics
S. Chidambara Raja, L. A. Kumaraswamidhas, M. Ramu
HEAT TRANSFER RESEARCH
(2020)
Article
Thermodynamics
Arunkumar Damodharan, Ramu Murugan, Syath Abuthakeer
