The Airplane Hangars of Pier Luigi Nervi: Digital and Scaled Models

2020 ◽  
Vol 61 (3) ◽  
pp. 187-200
Author(s):  
Giulio M. Barazzetta ◽  
Emilio Mossa ◽  
Carlo Poggi ◽  
Marco Simoncelli
Keyword(s):  
Finite Element ◽  
Finite Element Methods ◽  
Structural Models ◽  
Structural Behavior ◽  
Complex Structures ◽  
The Past ◽  
Starting Point ◽  
Complete Study ◽  
Scaled Models ◽  
Work Done

The paper presents a complete study of the work done by Pier Luigi Nervi for the design and construction of a series of concrete hangars between 1935 and 1940. This research is enclosed in the framework of the exhibition entitled "Pier Luigi Nervi, il modello come strumento di progetto e costruzione" that gathers researches from Università degli Studi di Bologna, Università di Roma Tor Vergata and Politecnico di Milano. The exhibition was used as a starting point for a general discussion about the meaning of the logical passage that leads engineers and architects from physical scaled models to numerical structural models. The Politecnico di Milano contributed to re-writing the first experiences of Pier Luigi Nervi and Arturo Danusso in the structural modeling. Scaled models, nowadays substituted by finite element methods, were widely used in the past, for the understanding of the structural behavior of complex structures. Unfortunately, many of these masterpieces have been destroyed during the years (as happened to the two original models tested by Pier Luigi Nervi and reproduced for the exhibition). <br/> In the last part of the paper, based on numerical results, the structural behavior of these hangars is deeply discussed, underlining all the principal strengths and weaknesses of these complex structures.

Evaluating and Improving Locomotive Crashworthiness Using LS-DYNA

2000 ◽  
Author(s):  
Stephen J. Kokkins ◽  
S. Kash Kasturi ◽  
Wayne Kong ◽  
S. K. John Punwani
Keyword(s):  
Finite Element ◽  
Structural Design ◽  
Structural Models ◽  
Structural Behavior ◽  
Right Of Way ◽  
Dynamic Finite Element ◽  
Rail Vehicles ◽  
Linear Material ◽  
The Right ◽  
Modeling Code

Abstract Representative structural models of locomotives, other rail vehicles, and other potential colliding objects were combined into moving consists which were then subjected to various collision scenarios. The LS-DYNA dynamic finite-element modeling code was utilized to realistically simulate collisions and guide understanding and improvements of the locomotive structures. This incorporated the effects of the collision interactions, plus critical non-linear material and structural behavior, buckling, fracture, kinematics, and wayside interactions of the vehicles. The types of collisions included: locomotive-headed consists striking standing consists obliquely fouling the Right Of Way, headed both by freight cars and other locomotives; locomotives striking loose, loaded intermodal containers dislodged from opposing cars on adjacent track. Work on multiple coupled locomotive overrides in direct consist collisions is now being conducted. The effects of varying parameters such as collision speeds, location and orientation of the colliding vehicles, and structural improvements were explored and quantified. Also, the effects of some structural design modifications such as stronger collision posts and cab structure were evaluated using this process. Verification studies to date have shown good correlation between the analytical simulations and observed outcome of actual historical accidents.

Reliability Indexes Calculation of Industrial Boilers Under Stochastic Thermal Process

1998 ◽  
Author(s):  
Olivier Rollot ◽  
Maurice Pendola ◽  
Maurice Lemaire ◽  
Igor Boutemy
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Finite Element Methods ◽  
Thermal Process ◽  
Complex Structures ◽  
The Finite Element Method ◽  
Random Data ◽  
Electric Company ◽  
New Methods ◽  
Industrial Boilers

Abstract This text sums up a research for the French Electric Company, EDF, which wants to know the influence of the temperature variability on the reliability of some of their boilers. These boilers are very complex structures whose behavior has to be modelized by the Finite Element Method, FEM. This work is an application of Finite Element Methods in a reliability context, that means the introduction of random data into a classical FEM, in order to determine the reliability of the structures. These random data may concern geometry, material characteristics of the structures or the loads the structure may carry. Then, it’s necessary to employ new methods to take into account these stochastic approaches and to obtain more efficient decision’s elements for a better control of the boilers.

Predicting the transient EM response of complex structures using the compact finite-element method

1989 ◽  
Vol 20 (2) ◽  
pp. 51 ◽  
Author(s):  
A. Raiche ◽  
F. Sugeng
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Finite Element Model ◽  
Target Identification ◽  
Structural Models ◽  
Element Model ◽  
Earth Model ◽  
Complex Structures ◽  
Identification Problems ◽  
Tem Method

The compact finite-element model (CFEM) method has been used to model the transient EM (TEM) response of an earth model consisting of a heterogeneous prism in a two-layered, conducting halfspace. The prism can be deformed to simulate any angle of dip and plunge without the effect of 'staircasing'. The present implementation of CFEM (program Samaya) allows for a horizontal-loop transmitter with arbitrarily oriented magnetic dipole receivers which may be on the surface or downhole. Samaya can be run on workstations or on augmented IBM PC-AT's (or clones).The use of Samaya should allow the TEM method to be used to solve a greater range of structural and target identification problems than is possible with existing interpretation aids. Having the ability to predict the TEM response of an expected geology means that surveys can be designed to yield optimum information. The program can also be used to validate hypothesized structural models against field data.The paper concludes with a discussion of the computed downhole TEM response of a dipping target.

Finite element methods for fractional diffusion equations

2020 ◽  
Vol 11 (04) ◽  
pp. 2030001
Author(s):  
Yue Zhao ◽  
Chen Shen ◽  
Min Qu ◽  
Weiping Bu ◽  
Yifa Tang
Keyword(s):  
Finite Element ◽  
Finite Element Methods ◽  
Regularity Theory ◽  
Fractional Diffusion ◽  
Diffusion Equations ◽  
Fractional Diffusion Equations ◽  
The Past ◽  
Time Space ◽  
Engineering Physics ◽  
Substantial Interest

Due to the successful applications in engineering, physics, biology, finance, etc., there has been substantial interest in fractional diffusion equations over the past few decades, and literatures on developing and analyzing efficient and accurate numerical methods for reliably simulating such equations are vast and fast growing. This paper gives a concise overview on finite element methods for these equations, which are divided into time fractional, space fractional and time-space fractional diffusion equations. Besides, we also involve some relevant topics on the regularity theory, the well-posedness, and the fast algorithm.

scholarly journals Numerical analysis of two pile caps with sockets embedded, subject the eccentric compression load

2013 ◽  
Vol 6 (3) ◽  
pp. 436-474
Author(s):  
R. G. Delalibera ◽  
J. S. Giongo
Keyword(s):  
Finite Element ◽  
Numerical Analysis ◽  
Numerical Simulations ◽  
Finite Element Methods ◽  
Normal Load ◽  
Structural Behavior ◽  
Compression Load ◽  
Linear Behavior ◽  
Non Linear ◽  
Pile Caps

The structural behavior of pile caps with sockets embedded is influenced by interface of column-socket, which can be smooth or rough. With intent to analyze the behavior of two pile caps with embedded socket, considering the friction between the column and the socket, with eccentric normal load, the numerical simulations were carried out, using a program based on the Finite Element Methods (FEM). In the numerical analysis the non-linear behavior of materials was considered, also the friction between the column and the socket. It was considered perfect bond between the reinforcement and the concrete around. It was observed that the embedded length is preponderant factor in the structural behavior of the analyzed element.

scholarly journals Rotorcraft fuselage mass assessment in early design stages

2021 ◽  
Author(s):  
Dominik B. Schwinn ◽  
Peter Weiand ◽  
Michel Buchwald
Keyword(s):  
Finite Element ◽  
Design Process ◽  
Finite Element Methods ◽  
Detailed Design ◽  
Early Design ◽  
Mass Estimation ◽  
Structural Part ◽  
Overall Design ◽  
The Past ◽  
Early Design Stages

AbstractLike the design of fixed-wing aircraft the design of rotorcraft is generally divided into the three consecutive phases of conceptual, preliminary and detailed design. During each phase the acquired results in turn serve as input for new calculations, thus increasing the detail level and information about the new concept, while uncertainties about the new design are reduced. An important aspect of the overall design process is the mass estimation in early design stages. The weight of the rotorcraft drives the design of many important components, such as the rotor(s), the propulsion system and, therefore, the required fuel. The fuselage is considered as the central structural part, since it connects all other components to each other and serves as protection of the occupants but in the past it often turned out to also be the heaviest part of all rotorcraft components. This paper shows an approach to estimate rotorcraft component masses using statistical methods based on existing rotorcraft but also an approach to use finite element methods that determine the structural airframe mass based on mission profiles, respectively, bearable load cases.

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