scholarly journals Plane trusses optimization by means of parametric design and genetic algorithms applying visual programming

2019 ◽  
Vol 20 (4) ◽  
pp. 1-10
Author(s):  
Hugo Félix Begliardo Olivero ◽  
Matías Bonelli Hernández
Keyword(s):  
Professional Practice ◽  
Computer Technology ◽  
Structural Engineering ◽  
Parametric Design ◽  
Visual Programming ◽  
Environmental Benefits ◽  
Engineering Practice ◽  
Additional Contribution ◽  
Structural Engineers ◽  
Made In

The optimization of structures is a wished goal, but it is not always achieved in engineering practice, due to either the large additional effort that it demands or the lack of necessary resources to carry it out. Structural engineers usually use batch procedures, consisting of utilizing the software, in which data are input, running the analysis and evaluating the results, along which it is decided whether the design is accepted or modifications must be made, in which case the process is repeated again. The consequence of this is that the final result, normally, will always be improvable. For that reason, the field of optimization has usually been reserved to the academia. The new currents of structural engineering seek optimization by means of parametric design and evolutionary computing. As an additional contribution to the use of these resources, the objective of this work is to present an algorithm developed through visual programming for sizing, shape and topology optimization of plane trusses of the classic Howe, Pratt or Warren typologies, and to highlight the advantages that the use of this resource provides for the professional work of structural engineers, since it allows them to develop their own algorithms without the need of previous knowledge of programming, and to achieve economic and environmental benefits from saving materials. All this configures a clear transfer of the advances of computer technology to professional practice, extending the frontiers of the academic sphere. As an example of application, a truss analyzed by traditional methods, without optimizing, and the same truss optimized with the aforementioned algorithm, are compared.

Suitable degree of crudeness in engineering practice

2019 ◽  
Author(s):  
Ivar Björnsson ◽  
Oskar Larsson Ivanov ◽  
Dániel Honfi ◽  
Henrik Gabrielsson ◽  
Martin Fröderberg ◽  
...  
Keyword(s):  
Structural Engineering ◽  
Structural Reliability ◽  
Decision Models ◽  
Structural Safety ◽  
Simplified Model ◽  
Engineering Practice ◽  
Uncertainty Principles ◽  
Engineering Models ◽  
Consistent Treatment ◽  
Structural Engineers

<p>Practicing structural engineers may be familiar with the main principles of structural reliability but may not necessarily be experts in using such methods. This may lead to a lack in understanding the effect of uncertainties on the ensuing structural safety and to sub-optimization of more traditional structural engineering aspects. The aim of the current paper is to highlight the importance of considering risks and uncertainties in design and to improve the awareness of practicing engineers to such considerations. The importance of a consistent treatment of uncertainties in structural engineering is brought to attention with focus on the modelling approaches which often underlie decisions. Different aspects discussed are: decision making in light of uncertainty, principles of consistent crudeness and the influence of engineering performance in practice on the safety of structures. A simplified model, considering strategies for improving engineering models, is considered and examples, based on simplified decision models, are also provided.</p>

A New Generation of Tools for the Design of Tall Buildings Subjected to Wind Loads

2008 ◽  
Author(s):  
Emil Simiu ◽  
Rene D. Gabbai
Keyword(s):  
Structural Engineering ◽  
Tall Buildings ◽  
Building Envelope ◽  
Force Balance ◽  
Wind Loads ◽  
Individual Member ◽  
Engineering Practice ◽  
Wind Effects ◽  
Uncertainty Estimates ◽  
Internal Forces

Current approaches to the estimation of wind-induced wind effects on tall buildings are based largely on 1970s and 1980s technology, and were shown to result in some cases in errors of up to 40%. Improvements are needed in: (i) the description of direction-dependent aerodynamics; (ii) the description of the direction-dependent extreme wind climate; (iii) the estimation of inertial wind effects induced by fluctuating aerodynamic forces acting on the entire building envelope; (iv) the estimation of uncertainties inherent in the wind effects; and (v) the use of applied wind forces, calculated inertial forces, and uncertainty estimates, to obtain via influence coefficients accurate and risk-consistent estimates of wind-induced internal forces or demand-to-capacity ratios for any individual structural member. Methods used in current wind engineering practice are especially deficient when the distribution of the wind loads over the building surface and their effects at levels other than the building base are not known, as is the case when measurements are obtained by the High-Frequency Force Balance method, particularly in the presence of aerodynamic interference effects due to neighboring buildings. The paper describes a procedure that makes it possible to estimate wind-induced internal forces and demand-to-capacity ratios in any individual member by: developing aerodynamic and wind climatological data sets, as well as aerodynamic/climatological directional interaction models; significantly improving the quality of the design via rigorous structural engineering methods made possible by modern computational resources; and properly accounting for knowledge uncertainties. The paper covers estimates of wind effects required for allowable stress design, wherein knowledge uncertainties pertaining to the parameters that determine the wind loading are not considered, as well as estimates required for strength design, in which these uncertainties need to be accounted for explicitly.

Crafting a framework of embodied carbon education, tracking, and reduction for US-based structural engineers

2021 ◽  
Author(s):  
Michael Gryniuk ◽  
Dirk Kestner ◽  
Luke Lombardi ◽  
Megan Stringer ◽  
Mark Webster ◽  
...  
Keyword(s):  
Climate Change ◽  
Global Warming ◽  
Structural Engineering ◽  
Professional Organizations ◽  
Structural System ◽  
Design Decisions ◽  
Collaborative Development ◽  
Climate Targets ◽  
Embodied Carbon ◽  
Structural Engineers

<p>Achieving reductions to embodied carbon, the global warming potential emissions due to the production of materials, is an essential component to meeting science-based climate targets. Studies have shown that a significant portion of embodied emissions within the built environment are due to structural materials. However, many structural engineers are, not only uneducated in the concept of embodied carbon, but also not aware of the role their decisions can make in addressing climate change. This is further exacerbated by a profession that does not have sufficient structural system embodied carbon benchmark information to make important and informed early design decisions. This required the collaborative development of a structural engineering commitment program, SE 2050, that is supported by leading professional organizations to spur the education and transformation of the profession.</p>

scholarly journals Evaluation of a Modified MPA Procedure Assuming Higher Modes as Elastic to Estimate Seismic Demands

2004 ◽  
Vol 20 (3) ◽  
pp. 757-778 ◽  
Author(s):  
Anil K. Chopra ◽  
Rakesh K. Goel ◽  
Chatpan Chintanapakdee
Keyword(s):  
Structural Engineering ◽  
Pushover Analysis ◽  
Computational Effort ◽  
Attractive Alternative ◽  
Engineering Practice ◽  
Seismic Demands ◽  
History Analysis ◽  
Modes Of Vibration ◽  
Response History Analysis ◽  
Damped Systems

The modal pushover analysis (MPA) procedure, which includes the contributions of all significant modes of vibration, estimates seismic demands much more accurately than current pushover procedures used in structural engineering practice. Outlined in this paper is a modified MPA (MMPA) procedure wherein the response contributions of higher vibration modes are computed by assuming the building to be linearly elastic, thus reducing the computational effort. After outlining such a modified procedure, its accuracy is evaluated for a variety of frame buildings and ground motion ensembles. Although it is not necessarily more accurate than the MPA procedure, the MMPA procedure is an attractive alternative for practical application because it leads to a larger estimate of seismic demands, improving the accuracy of the MPA results in some cases (relative to nonlinear response history analysis) and increasing their conservatism in others. However, such conservatism is unacceptably large for lightly damped systems, with damping significantly less than 5%. Thus the MMPA procedure is not recommended for such systems.

scholarly journals Mortars with CDW Recycled Aggregates Submitted to High Levels of CO2

2021 ◽  
Vol 6 (11) ◽  
pp. 159
Author(s):  
Ricardo Infante Gomes ◽  
David Bastos ◽  
Catarina Brazão Farinha ◽  
Cinthia Maia Pederneiras ◽  
Rosário Veiga ◽  
...  
Keyword(s):  
Large Scale ◽  
Mechanical Performance ◽  
Construction Materials ◽  
Environmental Benefits ◽  
Recycled Aggregates ◽  
Construction And Demolition Wastes ◽  
Short Period ◽  
Natural Aggregates ◽  
Cement Factories ◽  
Made In

Construction and demolition wastes (CDW) are generated at a large scale and have a diversified potential in the construction sector. The replacement of natural aggregates (NA) with CDW recycled aggregates (RA) in construction materials, such as mortars, has several environmental benefits, such as the reduction in the natural resources used in these products and simultaneous prevention of waste landfill. Complementarily, CDW have the potential to capture CO2 since some of their components may carbonate, which also contributes to a decrease in global warming potential. The main objective of this research is to evaluate the influence of the exposure of CDW RA to CO2 produced in cement factories and its effect on mortars. Several mortars were developed with a volumetric ratio of 1:4 (cement: aggregate), with NA (reference mortar), CDW RA and CDW RA exposed to high levels of CO2 (CRA). The two types of waste aggregate were incorporated, replacing NA at 50% and 100% (in volume). The mortars with NA and non-carbonated RA and CRA from CDW were analysed, accounting for their performance in the fresh and hardened states in terms of workability, mechanical behaviour and water absorption by capillarity. It was concluded that mortars with CDW (both CRA and non-carbonated RA) generally present a good performance for non-structural purposes, although they suffer a moderate decrease in mechanical performance when NA is replaced with RA. Additionally, small improvements were found in the performance of the aggregates and mortars with CRA subjected to a CO2 curing for a short period (5 h), while a long carbonation period (5 d) led to a decrease in performance, contrary to the results obtained in the literature that indicate a significant increase in such characteristics. This difference could be because the literature focused on made-in-laboratory CDW aggregates, while, in this research, the wastes came from real demolition activities, and were thus older and more heterogeneous.

scholarly journals Detection of children with bronchopulmonary pathology and risk of its forming using the «EDIFAR» computer system

2003 ◽  
Vol 2 (4) ◽  
pp. 96-103
Author(s):  
T. V. Zabolotskikh ◽  
Yu. L. Mizernitsky ◽  
L. A. Dartau
Keyword(s):  
Health Service ◽  
Computer System ◽  
Computer Technology ◽  
Respiratory Diseases ◽  
Health Protection ◽  
Official Statistic ◽  
Insurance Medicine ◽  
Primary Health ◽  
Actual Prevalence ◽  
Made In

In the article it has been shown the efficiency of children detection with bronchopulmonary pathology and risk of its forming using the «EDIFAR» computer system. Screening with this computer technology allows in short terms a pictorial view of children’s health on the primary health service territory. This investigation has been made in pediatric polyclinic ‹ 4 in Blagoveshchensk. The results show the actual prevalence of respiratory diseases at children aged 0—7 years and are an evidence of a significant exceeding of disease indices as compared to the official statistic data. Information get with the computer system is necessary not only for address aid but is useful in conditions of insurance medicine and market principles of funds spending for health protection as well.

scholarly journals Bond-Graph model based stepper motor output characteristics simulation implemented in LabVIEW environment

2021 ◽  
Vol 7 (1.) ◽  
Author(s):  
Zsolt Molnár
Keyword(s):  
Block Diagram ◽  
Real Life ◽  
Graph Model ◽  
Bond Graph ◽  
Visual Programming ◽  
Stepper Motor ◽  
Intermediate Step ◽  
Virtual Device ◽  
Wide Range ◽  
Made In

In the industry, simulations are of great importance. They enable measurements to be made in different conditions about a virtual device, which are highly comparable to measurements made in a real life scenarios. Because of their wide range of usage in lower power drive systems, where precision and simplicity is a must, the subject of study is a permanent magnet stepper motor. For precise positioning purposes, it is essential to know the positioning behaviour of these devices. The model construction process involved an intermediate step, which consisted of creating the Bond-Graph of the motor based on pre-defined models available in the literature in this field. In the next step, the Bond-Graph model was converted to a block diagram of the motor. This permitted the direct implementation of the motor model in LabVIEW visual programming environment. The preliminary steps allows us to check and confirm the functionality and correctness of the model. This article covers in detail the model conversion and implementation steps of the simulation. At the end, the functionality of the simulation was tested.

scholarly journals Earthquakes and tall buildings

1970 ◽  
Vol 3 (2) ◽  
pp. 51-59
Author(s):  
Paul C. Jennings
Keyword(s):  
Structural Engineering ◽  
Tall Buildings ◽  
Technical Detail ◽  
Structural Engineers

Editor’s Note: Professor Jennings' contribution is, he says, "relatively non-technical, and is aimed primarily at laymen and engineers not directly engaged in structural engineering". Papers of this sort are so rare that we are delighted to offer this one from so respected an authority as Professor Jennings, not only for those of our members that the Professor intended should benefit, but also for structural engineers. All of us, deeply involved with technical detail, tend to lose something of our appreciation of the overall problem.

scholarly journals Selective interference: Emergent complexity informed by programmatic, social and performative criteria

2021 ◽  
Author(s):  
◽  
Christopher David Welch
Keyword(s):  
Programming Languages ◽  
Design Process ◽  
Parametric Design ◽  
Research Process ◽  
Visual Programming ◽  
Space Planning ◽  
Site Analysis ◽  
Box Structure ◽  
Barrier To Entry ◽  
High Level

<p>Parametric design tools and visual programming languages are fast becoming an important part of the architects design process. A review of current literature notes that the barrier to entry into the medium is lowering while the power of the tools available is increasing. The purpose of this research is to use these emerging tools to explore complex architectural issues related to space planning and massing. This research aims to bring these aspects of the design process together to generate an architecture where programme and aesthetic are derived in equal measure by the architect and the computer. The project began with a series of technical studies focusing primarily on space planning, massing, site analysis and circulation with the purpose of using an amalgamation of these techniques to develop into a final generative algorithm. These ideas are explored through an open ended design process of iterative research and testing, self and peer review, development and critical reflection. The viability of the algorithm is then tested through the generation a number of test buildings, across variety of sites. In order to provide a direction and author a degree of creative friction within the research process, the projects are framed around the development of a mid-size, urban sited secondary school. The final algorithm provides constraints in such a way that the architecture evolves in a natural, predictable way that can still surprise and inform, as well as consistently producing viable, interesting iterations of buildings. This process, described as an “open box” structure, produced a wide variety of working concepts and provided a high level of control as a designer.</p>

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