A novel device to improve robustness of end plate beam–column connections: Analytical model development

2022 ◽  
Vol 172 ◽  
pp. 108878
Author(s):  
Mohamed A. Shaheen ◽  
Andrew S.J. Foster ◽  
Lee S. Cunningham
2021 ◽  
Vol 255 ◽  
pp. 112906
Author(s):  
Wafaa El Masnaoui ◽  
Alain DaidiÉ ◽  
Frédéric Lachaud ◽  
Christian Paleczny

Author(s):  
Qingwen Deng ◽  
Yuyi Lin

Abstract This paper presents a one-dimensional analytical model of the ram extrusion process of a powdered material and a procedure for optimizing the shape of the extrusion die. Powdered coal mixed with water and asphalt was used as the extrudate material in the model development. The analytical model relates the pressure at the entrance of the die to the exit pressure of the die. Certain key parameters of the model were obtained from experiments. The comparison of the inlet pressure derived from the analytical model and the value obtained from the experimental procedure shown a good agreement. Optimization algorithms were applied to generate the ideal die shape. The objective is to minimize the power consumed in the extrusion process, while maintaining maximum strength for the extrudates. It is concluded from the study that the model and the optimization procedure developed for the model can be used in extrusion studies of other powdered materials.


Author(s):  
Jaeho Kwak ◽  
Bin Yao ◽  
Anil Bajaj

This paper presents a detailed analytical model development which can describe the dynamic behavior of the electromechanical brake-by-wire (BBW) system over the entire operating range. The complete model has 10 degree-of-freedom (DOF) and includes essential nonlinearities such as gear backlashes, Coulomb frictions, and disk gap clearance. Such a full model is reduced to 6 degree-of-freedom model in SIMULINK for simulation study of the effectiveness and the achievable performance of different hardware and controller designs, an invaluable tool in the early design stage of a product. Simulation results show that the model is able to reproduce various nonlinear characteristics including typical structural hysteresis as shown in real brake assembly. The linearized version of the full nonlinear model is then obtained for its modal properties to understand the modes that are critical to the low frequency dynamics of the overall system. The results of the modal analyses are subsequently utilized to obtain two simplified models, one for non-contact mode and the other for the contact mode of operation. The concepts of two simplified models well capture the dynamic characteristics of the system over the frequencies of interest and are being used in the controller (e.g., clamping force control) and estimator (e.g., gap clearance estimation) designs that are under investigation.


2014 ◽  
Vol 7 (4) ◽  
pp. 638-660 ◽  
Author(s):  
Asbjørn Rolstadås ◽  
Iris Tommelein ◽  
Per Morten Schiefloe ◽  
Glenn Ballard

Purpose – The purpose of this paper is to show that project success is dependent on the project management approach selected, relative to the challenges posed by the project, and to develop an analytical model for analyzing the performance of the project organization. Design/methodology/approach – The research is based on literature review, model development, interviews, and case studies. Findings – The findings define two different approaches in project management: The prescriptive approach focusses on the formal qualities of the project organization, including governing documentation and procedures. The adaptive approach focusses on the process of developing and improving a project organization, project culture and team commitment. The two approaches have been identified through studies of three different case projects. An analytical model, referred to as the Pentagon model, has been applied for analyzing the performance of the project organization and explaining the project management approach. The model focusses on five different organizational aspects: structure, technologies, culture, social relations and networks, and interaction. Research limitations/implications – The research is limited to megaprojects and to project management success. Practical implications – It is suggested that project teams consider and select their project management approach at project initiation, and accordingly decide on relevant success factors to focus on. The adapted Pentagon model can be applied to develop the project management organization and assess its performance in the course of project delivery. Originality/value – The contribution of the research is the application of the analytical model, and the identification as well as illustration of the prescriptive, vs adaptive management approach.


2018 ◽  
Vol 43 (3) ◽  
pp. 245-253 ◽  
Author(s):  
Mashallah Rezakazemi ◽  
Saeed Shirazian

AbstractNanostructured ceramic membranes have shown considerable separation performance. In this work, an analytical model is developed to evaluate the separation performance of porous ceramic membranes in gas separation applications. The model takes into account three layers, i. e., (1) active layer, (2) interlayer, and (3) support layer. For estimation of sorption at the interface of feed stream and membrane, the partition coefficient model was used and the unsteady-state conservation of mass equation coupled to molecular models of the diffusivity coefficient was used to predict the permeation of penetrant hydrogen gas through a ceramic membrane. It was observed that the model can be readily applied to other systems of interest as a predictive tool.


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