scholarly journals Parametric Analysis of a Spiraled Shell: Learning from Nature’s Adaptable Structures

Designs ◽  
2018 ◽  
Vol 2 (4) ◽  
pp. 46
Author(s):  
Diana Chen ◽  
Brandon Ross ◽  
Leidy Klotz
Keyword(s):  
Structural Design ◽  
Growth Process ◽  
Structural Integrity ◽  
Building Design ◽  
Shell Wall ◽  
Quantitative Studies ◽  
Infrastructure Design ◽  
Structural Adaptability ◽  
Parametric Studies ◽  
Shell Wall Thickness

In our current building design philosophy, structural design is based on static predictions of the loads a building will need to withstand and the services it will need to provide. However, one study found that 60% of all buildings are demolished due to obsolescence. To combat our obsolescence-demolition culture, we turn to Nature for lessons about adaptable structural design. In this paper, we investigate the structural adaptability of the T. terebra spiraled turret shell through finite element modeling and parametric studies. The shell is able to change its structure over time to meet changing performance demands—a feat of adaptability that could transform our current infrastructure design. Modeling the shell’s growth process is an early and simple attempt at characterizing adaptability. As the mollusk deposits material overtime, its shell wall thickness changes, and its number of whorls increases. We designed parametric studies around these two modes of growth and investigated their effect on structural integrity and living convenience for the mollusk. By drawing parallels between the shell structure and human structures, we demonstrate connections between engineering challenges and Nature’s solutions. We encourage readers to consider biomimicry as a source of inspiration for their own quantitative studies for a more sustainable world.

Critical Section Selection Methodology for the U.S. EPR™ Standard Nuclear Power Plant

2010 ◽  
Author(s):  
Se-Kwon Jung ◽  
Adam Goodman ◽  
Joe Harrold ◽  
Nawar Alchaar
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Structural Design ◽  
Nuclear Power ◽  
Structural Integrity ◽  
Safety Evaluation ◽  
Critical Section ◽  
Selection Methodology ◽  
Critical Sections ◽  
The U.S

This paper presents a three-tier, critical section selection methodology that is used to identify critical sections for the U.S. EPR™ Standard Nuclear Power Plant (NPP). The critical section selection methodology includes three complementary approaches: qualitative, quantitative, and supplementary. These three approaches are applied to Seismic Category I structures in a complementary fashion to identify the most critical portions of the building whose structural integrity needs to be maintained for postulated design basis events and conditions. Once the design of critical sections for a particular Seismic Category I structure is complete, the design for that structure is essentially complete for safety evaluation purposes. Critical sections, taken as a whole, are analytically representative of an “essentially complete” U.S. EPR™ design; their structural design adequacy provides reasonable assurance of overall U.S. EPR™ structural design adequacy.

JSME Construction Standard for Superconducting Magnet of Fusion Facility “Procedure for Structural Design”

2009 ◽  
Author(s):  
Yukio Takahashi ◽  
Shigeru Tado ◽  
Kazunori Kitamura ◽  
Masataka Nakahira ◽  
Junji Ohmori ◽  
...  
Keyword(s):  
Stainless Steels ◽  
Structural Design ◽  
Structural Integrity ◽  
Superconducting Magnets ◽  
Austenitic Stainless Steels ◽  
Superconducting Magnet ◽  
Fatigue Curve ◽  
Stress System ◽  
Allowable Stress ◽  
Fatigue Assessment

Superconducting magnets are structures which have an important role in Tokamak-type fusion reactor plants. They are huge and complicated structures exposed to very low temperature, 4K and the methods for keeping their integrity need to be newly developed. To maintain their structural integrity during the plant operation, a procedure for structural design was developed as a part of JSME Construction Standard for Superconducting Magnet. General structures and requirements of this procedure basically follow those of class 1 and class 2 components in light water reactor plants as specified in Section III, Division 1 of the ASME Boiler and Pressure Vessel Code, and include the evaluation of primary stress, secondary stress and fatigue damage. However, various new aspects have been incorporated considering the features of superconducting magnet structures. They can be summarized as follows: (i) A new procedure to determine allowable stress intensity value was employed to take advantage of the excellent property of newly developed austenitic stainless steels. (ii) Allowable stress system was simplified considering that only austenitic stainless steels and a nickel-based alloy are planned to be used. (iii) A design fatigue curve at 4K was developed for austenitic stainless steels. (iv) In addition to the conventional fatigue assessment based on design fatigue curves, guidelines for fatigue assessment based on crack growth prediction were added as a non-mandatory appendix to provide a tool of assurance for welded joints which are difficult to evaluate nondestructively during the service.

Design Equation for Minimum Required Thickness of a Cylindrical Shell Subject to Internal Pressure Based on Von Mises Criterion

2019 ◽  
Author(s):  
James Lu ◽  
Barry Millet ◽  
Kenneth Kirkpatrick ◽  
Bryan Mosher
Keyword(s):  
Cylindrical Shell ◽  
Internal Pressure ◽  
Yield Criterion ◽  
Design Equation ◽  
Shell Wall ◽  
Section Viii ◽  
Von Mises Yield Criterion ◽  
Von Mises ◽  
Division 2 ◽  
Shell Wall Thickness

Abstract Design equation (4.3.1) for the minimum required thickness of a cylindrical shell subjected to internal pressure in Part 4 “design by rule (DBR)” of the ASME Boiler and Pressure Vessel Code, Section VIII, Division 2 [1] is based on the Tresca Yield Criterion, while design by analysis (DBA) in Part 5 of the Division 2 Code is based on the von Mises Yield Criterion. According to ASME PTB-1 “ASME Section VIII – Division 2 Criteria and Commentary”, the difference in results is about 15% due to use of the two different criteria. Although the von Mises Yield Criterion will result in a shell wall thickness less than that from Tresca Yield Criterion, Part 4 (DBR) of ASME Division 2 adopts the latter for a more convenient design equation. To use the von Mises Criterion in lieu of Tresca to reduce shell wall thickness, one has to follow DBA rules in Part 5 of Division 2, which typically requires detailed numeric analysis performed by experienced stress analysts. This paper proposes a simple design equation for the minimum required thickness of a cylindrical shell subjected to internal pressure based on the von Mises Yield Criterion. The equation is suitable for both thin and thick cylindrical shells. Calculation results from the equation are validated by results from limit load analyses in accordance with Part 5 of ASME Division 2 Code.

scholarly journals Special Issue “Digital Twin Technology in the AEC Industry”

2020 ◽  
Vol 2020 ◽  
pp. 1-18
Author(s):  
Jisong Zhang ◽  
Lihua Zhao ◽  
Guoqian Ren ◽  
Haijiang Li ◽  
Xiaofei Li
Keyword(s):  
Structural Design ◽  
Structural Engineering ◽  
Sustainable Design ◽  
Building Design ◽  
Current Situation ◽  
Special Issue ◽  
Sustainable Building ◽  
Digital Twin ◽  
The Past ◽  
The Future

Sustainable building design has become a hot topic over the past decades. Many standards, databases, and tools have been developed for achieving a sustainable building. Not until recently have the importance of structural engineering and its contribution to sustainable building design been full recognised. However, due to the highly fragmented and diversity of knowledge across building and infrastructure domains, there is a lack of approach that can address all the sustainable issues within the structural design. This paper reviews the sustainable design from the perspective of structural engineering: (1) reviewing the current situation; (2) identifying the gaps and difficulties; and (3) making recommendations for future improvements. The strategies and indicators, as well as BIM-enabled methodology, for sustainable structural design (SSD) are also discussed in a holistic way. The results of this investigation show that most of the methods are not doing well in terms of delivering a successful sustainable structural design. It is expected that the future BIM could probably provide such a platform to address these issues.

Predicted Thermal Stresses in a Trimaterial Assembly With Application to Silicon-Based Photovoltaic Module

2013 ◽  
Vol 80 (2) ◽  
Author(s):  
E. Suhir ◽  
D. Shangguan ◽  
L. Bechou
Keyword(s):  
Cross Sections ◽  
Structural Design ◽  
Thermal Stresses ◽  
Structural Integrity ◽  
Crystalline Silicon ◽  
Photovoltaic Module ◽  
Thermally Induced ◽  
Short And Long Term ◽  
Silicon Based

Low-temperature thermally induced stresses in a trimaterial assembly subjected to the change in temperature are predicted based on an approximate structural analysis (strength-of-materials) analytical (“mathematical”) model. The addressed stresses include normal stresses acting in the cross-sections of the assembly components and determining their short- and long-term reliability, as well as the interfacial shearing and peeling stresses responsible for the adhesive and cohesive strength of the assembly. The model is applied to a preframed crystalline silicon photovoltaic module (PVM) assembly. It is concluded that the interfacial thermal stresses, and especially the peeling stresses, can be rather high, so that the structural integrity of the module could be compromised, unless appropriate design for reliability measures are taken. The developed model can be helpful in the stress analysis and physical (structural) design of the PVM and other trimaterial assemblies.

scholarly journals Automated Structural Design of Shear Wall Residential Buildings Using GAN-Based Machine Learning Algorithm

2020 ◽  
Author(s):  
Xinzheng Lu ◽  
Wenjie Liao ◽  
Yuli Huang ◽  
Zhe Zheng ◽  
Yuanqing Lin
Keyword(s):  
Structural Design ◽  
Learning Algorithm ◽  
Design Method ◽  
Residential Buildings ◽  
Confusion Matrix ◽  
Building Design ◽  
Shear Wall ◽  
Generative Adversarial Network ◽  
Adversarial Network ◽  
Design Documents

Abstract Artificial intelligence is transforming many industries and reshaping building design processes to be smarter and automated. While a large number of studies on automated building design have been carried out recently, they focused on architectural aspects, leaving a gap in its application to structural design. Considering the increasingly wide application of shear wall systems in high-rise buildings and envisioning the massive benefit of automated structural design, this paper proposes a shear-wall design automation model based on a generative adversarial network (GAN). Its goal is to learn from existing shear wall design documents and then perform structural design intelligently and swiftly. To this end, a database of representative architectural and structural design documents was developed. Then, datasets were prepared via abstraction, semanticization, classification, and parameterization in terms of building height and seismic design category. The GAN model improved its shear wall design proficiency through adversarial training supported by data and hyper-parametric analytics. The performance of the trained GAN model was appraised against the metrics based on the confusion matrix and the intersection-over-union approach. Finally, case studies were conducted to evaluate the applicability, effectiveness, and appropriateness of the innovative GAN-based structural design method.

scholarly journals Structural Design and its Improvements Through the Development of the XF3-30 Engine

1988 ◽  
Author(s):  
Hidekatsu Kikuchi ◽  
Kiyoshi Ishii
Keyword(s):  
Structural Design ◽  
Structural Integrity ◽  
Structural Features ◽  
Flight Time ◽  
Qualification Test ◽  
Structural Problems ◽  
Self Defence ◽  
Made In

The XF3-30 engine has been successfully completed its Qualification Test at March 1986 and the production has started as the powerplant for Japan Self Defence Force’s intermedeate trainer T-4. The first flight of the T-4 powered by two XF3-30 engine was made on the 29th July 1985. More than 500 test flights have been made in these two years and engine flight time has accumulated to over 1,500 hours. This XF3-30 engine has been imposed strict requirements of the structural integrity to meet the MIL-E-5007D specification. This paper describes the structural features of this engine and some structural problems encountered through the development. The improvements for these development problems are covered.

scholarly journals STRUCTURAL DESIGN PROCEDURES FOR CONCRETE ARMOUR UNITS

1984 ◽  
Vol 1 (19) ◽  
pp. 172 ◽  
Author(s):  
Kevin R. Hall ◽  
W.F. Baird ◽  
D.J. Turcke
Keyword(s):  
Structural Design ◽  
Rational Design ◽  
Structural Integrity ◽  
Design Procedure ◽  
Analytical Techniques ◽  
Structural Performance ◽  
Design Procedures ◽  
Design Loads ◽  
Resultant Stress ◽  
Hydraulic Stability

A rational design procedure for rubblemound breakwater protection which will ensure both the structural integrity and hydraulic stability of individual concrete armour units and the overall armour system is presented. The procedure involves new experimental techniques for measuring strains in model concrete armour units in a hydraulic model of a breakwater subjected to simulated prototype wave attack and analytical techniques for determining equivalent prototype loads on units. Selected design loads are used to define the resultant stress distribution to allow the designer to take the necessary measures to ensure the structural performance of the unit in a breakwater environment•

Validation of a Finite Element Toolbox for Studying Flaw Interaction

2020 ◽  
Author(s):  
Harry E. Coules
Keyword(s):  
Finite Element ◽  
Fracture Mechanics ◽  
Large Scale ◽  
Structural Integrity ◽  
Three Dimensional ◽  
Integrity Assessment ◽  
Linear Elastic ◽  
Wide Range ◽  
Parametric Studies ◽  
Elastic Crack

Abstract Structural integrity assessment often requires the interaction of multiple closely-spaced cracks or flaws in a structure to be considered. Although many procedures for structural integrity assessment include rules for determining the significance of flaw interaction, and for re-characterising interacting flaws, these rules can be difficult to validate in a fracture mechanics framework. int_defects is an open-source MATLAB toolbox which uses the Abaqus finite element suite to perform large-scale parametric studies in cracked-body analysis. It is designed to allow developers of assessment codes to check the accuracy of simplified interaction criteria under a wide range of conditions, e.g. for different interacting flaw geometries, material models and loading cases. int_defects can help analysts perform parametric studies to determine linear elastic crack tip stress field parameters, elastic-plastic parameters and plastic limit loads for simple three-dimensional cracked bodies relevant to assessment codes. This article focusses on the validation of int_defects using existing fracture mechanics results. Through a set of validation examples, int_defects is shown to produce accurate results for a very wide range of cases in both linear and non-linear cracked-body analysis. Nevertheless, it is emphasised that users of this software should be conscious of the inherent limitations of LEFM and EPFM theory when applied to real fracture processes, and effects such as constraint loss should be considered when formulating interaction criteria.

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