24,780 research outputs found
Design and characterization of variable stiffness structural joints
Get PDFThis paper presents design and characterization of a new type of structural joint which can vary its stiffness through actuation. Stiffness variation is employed to control the dynamic response of frame structures equipped with such joints. The joint is made of a shape memory polymer (SMP) core which is reinforced by an SMP-aramid composite skin. A controlled stiffness reduction of the joint core material, induced by resistive heating, results in a shift of the structure natural frequencies. This work comprises two main parts: 1) characterization of material thermomechanical properties and viscoelastic behavior; 2) numerical simulations of the dynamic response of a 1-story planar frame equipped with two such variable stiffness joints. The experimental material model obtained through Dynamic Mechanical Analysis has been used to carry out modal and non-linear transient analysis. However, control time delays due to heating and cooling as well as fatigue are not considered in the numerical simulations. Results have shown that through joint stiffness control, the fundamental frequency shifts up to 8.72% causing a drastic reduction of the dynamic response under resonance loading. The SMP-aramid skin is effective to restrain the joint deformation in the activated state while maintaining viscoelastic damping properties.IMA
Structural adaptation through stiffness tuning
Get PDFAdaptive design strategies have been employed to improve structural performances in terms of load-bearing efficiency and energetic impact as well as to achieve multi-functionality. In this work, we investigate a passive adaptation strategy that employs variable stiffness in robotically printed materials. This paper focuses on the design and robotic fabrication of a chaise longue that can change shape to function as both recliner and chair depending on user requirements. The approach is unique in the way computational design is linked with robotic production. In this context, the design of the chaise longue is not limited to a formal process, but extends to the synthesis of the material distribution layout in order to achieve the intended functional behaviour.Cyber-physical Architecture #2: Apparatisation in & of Architecture ISBN 978-94-6366-200-0Architectural Engineerin
Sustainable Structural Design: Comprehensive Literature Review
No full textResearch on sustainable structural design (SSD) has increased significantly over the past decade. Having established the importanceof structural engineering in sustainable development, researchers and practitioners have developed sustainable design strategies to address theimpact of structural systems on the environment, economy, and society. Nevertheless, many studies have pointed out the inadequacy of existingassessment tools and the lack of overall understanding regarding the role of civil engineers and structural engineers in achieving sustainable goals.The purpose of this paper is to provide a comprehensive state-of-the-art overview of SSD, focusing on design strategies, parameters for SSD, andthe role of SSD in Green Building rating systems and building codes. First, the authors will clearly identify research results in this field and thenpoint out the biggest issues when choosing SSD strategies and evaluation parameters. To conclude, this paper will discuss the characteristic tasksof structural engineers with a particular emphasis on the concepts of structural performances, design service-life, and probabilistic approach
Bio-Based Composite Footbridge: Design, Production and In Situ Monitoring
Get PDFThis paper deals with the design, production and monitoring of a bio-composite footbridge with a span of 14 m across the river Dommel in the city of Eindhoven, the Netherlands. The specific bio-composite material that was used for this research is a Natural Fibre Reinforced Bio-Polymer (NFRBP). The goal of the research is to prove that NFRBP can be applied as a load-bearing structure in an outdoor environment. For this purpose, a multidisciplinary team of academic researchers from two universities and from the Centre of Expertise Biobased Economy, together with a manufacturer from the NFRBP industry, have developed a feasible design that could be produced in a short period of time and within a limited budget. The footbridge was designed, built and installed within less than one year. In the two years after the installation of the footbridge, the structural behaviour of the bridge was monitored by means of optical fibre glass strands, integrated within the structure, with the purpose of measuring deformations and change in elasticity that occur over time.Structural Design & MechanicsOLD Structural Desig
The Sustainable Highway for Environmentally Constrained Urbanized Areas
No full textThe ‘Sustainable Highway’ concept offers an integrated solution to motorway emission and noise problems. It consists of a motorway canopy made of cold-bendable laminated glass. Key factors here are durability, safety, cost and revenue. The design yields a significant reduction in noise, fine particulates, NOx, and CO2 and also in the use of fossil fuels. It also reduces the infrastructure footprint, freeing up building land in urban environments. The Sustainable Highway makes it possible to increase road capacity, boosts urban accessibility and supports government policy aimed at concentrating new building possibilities in urban environments. Special attention will be given in this paper to a possible structural system of the highway canopy and to the costs and benefits of the concept, compared with a highway with sound barrier
Incorporating sustainable development principles into building design: a review from a structural perspective including case study
Get PDFThe incorporation of sustainable development (SD) principles into all industries is increasingly important. The contribution of the building industry to a wide range of environmental impacts is extensive with the construction, operation and maintenance of buildings accounting for approximately 50% of all energy usage and anthropogenic greenhouse gas (GHG) emissions globally. In the building design process, structural engineers play a limited role in the sustainability of a design. The decisions on the incorporation of such aspects are usually at the mercy of the architect and client. A literature review was conducted to record and present the variability in research on issues directly related to the environmental performance of structures. There are inconsistencies in the published contribution of embodied energy (EE) and proportion of life cycle energy usage in structures. Outcomes demonstrate that due to this variability, environmental performance of structures is difficult to validate. A systematic approach beginning with standardised calculation procedure and database generation for EE of building materials is essential for practitioners to deliver sustainable structural designs. An analysis of a typical concrete office structure indicates potential benefits through the use of quantifiable environmental performance measures, delivering efficient solutions. Comparisons of slab construction techniques indicate overall EE reductions up to 40% being achievable.Griffith Sciences, Griffith School of EngineeringFull Tex
Mapping structural engineering strategies for sustainable development
No full textConsidering current trends in the Netherlands with regards to sustainability, there is a strong desire at Delft University of Technology to incorporate sustainable structural design strategies in the civil and structural engineering curriculum. Based on literature study and own experiences in practice, a coherent approach was developed, that can help students and practitioners to increase sustainability in their projects. The approach consists of a roadmap with 4 key strategies: increase lifespan of existing structures by reusing them, increase lifespan of existing structural elements by reusing them, design future proof and with a long-life span, and optimise the design for environmental impact. The strategies are explained and illustrated with examples.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Applied Mechanic
Study of optimisation strategies for aircraft structural design
Get PDFOptimisation plays an important role in structural design. Structural design
optimisation is not only a matter of weight reduction of the structure; it can be
used to optimise any type of objectives. In engineering practise, it is also
common to maximise performance parameters such as the maximum load
capacity and the fatigue life of a structure. Besides, the structural design in
modern commercial aircrafts inevitably involves considerations such as
aerodynamic performance and system requirements. Therefore the optimisation
of structural design usually has various disciplines to be taken account of.
Hence, the single objective, multi-objective and multi-disciplinary optimisation
problems are very important in engineering practise.
The aims of this research project are to classify and summarise typical
optimisation applications and their objectives and constraints in aircraft
structural design to help engineers to solve their optimisation problems. In
addition, this study aims to develop a systematic framework and
recommendations for approaches to various problems in this domain to inspire
engineers to solve their optimisation problems.
To achieve this objective, a literature review is carried out, focussing on four
aspects: Modelling of CAD structures, Finite element analysis of structures,
Structural Optimisation and Mathematical Optimisation. In addition, a survey
was undertaken with 15 experts with different backgrounds from Europe and
other countries. Meanwhile, three experts in aerospace industry are called for
an interview.
This thesis also presents the engineering applications in various aircraft
components. The fuselage component multi-disciplinary (structural, acoustics
and thermal) optimisation is discussed. In terms of the wing component, the
space unit of the wing box is defined for optimisation, and different constraints
for different parts are summarised. In addition, brief introduction of other
component optimisations are introduced.
This thesis also presents the development of a systematic framework for the
aircraft structural optimisation approaches. The general approach, and the DOE
& Algorithmic approach are defined and adopted in the framework. A framework
chart is illustrated to help engineers to initialise their problems in the initial
phase and cope with them following the workflow of the framework chart. In
order to highlight useful and practical suggestions for the engineers and
designers, recommendations are presented in this thesis.
Case studies are carried out to demonstrate and validate the function of the
framework. There are three case studies in this thesis, and all of them are from
industries. The first one is a door hinge with single-objective topology
optimisation problem. The second one is a crank with multi-objective shape
optimisation problem. And the third one is a landing gear torsion link with a
combined (topology, shape and sizing) optimisation problem. HYPERWORKS is
adopted to conduct the optimisation, which includes built-in parameterised tools
to generate the mesh solver, carry out the finite element analysis, and optimise
the design with various algorithms.
This study indicates that the optimisation is not always applicable in every
phase of the design. The preliminary phase is crucial for the entire optimisation.
The optimisation framework developed in this study can be systematically
applied in aircraft structural design. Engineers should learn about the DOE and
algorithmic approach in order to solve the multi-objective or multi-disciplinary
problem, and the approach framework developed in this study could provide a
good guideline
Rethinking Design Education: The Role of Universal Design in a Sustainable Future
Get PDFThis paper explores the critical gap in integrating Universal Design (UD) into U.S. design education, where sustainability is often prioritized while inclusivity remains elective. Through an ongoing study of 60 universities, initial findings reveal that only two briefly mention UD, and none fully integrate it into their core design programmes. This highlights a disconnect between inclusive values and educational structures. UD, like sustainability, offers broad social and commercial benefits by reducing stigma, expanding markets, and fostering equity. By embedding UD into foundational courses, design education can better prepare students to address environmental and social challenges. This paper argues for UD’s structural inclusion, not as an add-on, but as a key framework for shaping equitable and sustainable futures in design.This article is published as Oro, B., & Malhotra, S. (2024). Rethinking Design Education: The Role of Universal Design in a Sustainable Future. Diid, Dec 2024, 84(10);
https://doi.org/10.30682/diid8424
Sustainable Development of the Nile River at Greater Khartoum
No full textSudan is the largest country in Africa, but there is poverty and a lack of infrastructure, skills and opportunity despite its substantial natural resources. The capital of Sudan is Khartoum City,
located at the confluence of the Blue and White Nile Rivers. Unfortunately development on Nile
River Front is limited due to the risk of flooding and erosion. There is a danger that rapid
economic development may take place in this unique area without sustainable development
planning. This research project aims to develop strategies to protect the Nile River banks by
suitable stabilization methods so that development can take place safely.
Data has been collected about hydrology, morphology, geotechnical factors, soil classifications, river pattern systems, driving forces, and the main problems restricting sustainable development and engineering works for the Nile River. In addition the following have been reviewed: historical background, existing land uses, current environmental situations, and the economic and social conditions of the study areas. Research identified Cairo, Egypt as a similar case study, where data collected by the author included historical background, current situations, strategic visions and development plan for Nile River Shores. Further information was collected about sustainable development from a general literature review.
From these collected data a set of guidelines and indicators for sustainable development was
established related to environmental, economic and social factors. Based on those guidelines and
indicators, methods of stabilization of the banks for each shore were specified and a proposed
development plan was established. Methods of stabilization of banks and the development plan
were refined and evaluated to establish a final version of the development plan: Sustainable
Development of the Nile River Front (SDNRF) at Greater Khartoum. From refinement and evaluations, barriers and constraints for implementation were specified with their suggested
solutions. Finally, conclusions and recommendations related to the SDNRF Manual about
development and regulations were established
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