Fatigue of aircraft structures has become a major subject for research in the past ten years and the importance of establishing safe lifetimes for operation of aircraft or for…
Abstract
Fatigue of aircraft structures has become a major subject for research in the past ten years and the importance of establishing safe lifetimes for operation of aircraft or for replaceable structural components is now recognized. Some major contributions have been made to the knowledge of this subject, including methods of life assessment, determination of the fatigue resistance of several types of complete aircraft wing structure by laboratory test and some more fundamental studies of fatigue. The fatigue problem is considerably better understood than it was ten years ago and it can now be said with certainty where the most serious gaps lie. Information on two of these topics—namely, scatter, and the effect of random loading sequences—is being sought in the research programmes now proceeding at the Aeronautical Research Laboratories. Because of the vastness of the field a plea is made for greater inter‐change of information on the results of fatigue tests in all countries.
THIS Conference, the largest ever arranged on the subject of fatigue of metals, was sponsored by The Institution of Mechanical Engineers in co‐operation with The American Society…
Abstract
THIS Conference, the largest ever arranged on the subject of fatigue of metals, was sponsored by The Institution of Mechanical Engineers in co‐operation with The American Society of Mechanical Engineers. A follow‐up Conference of the A.S.M.E. was to be held in New York from November 28–30.
Under this heading are published regularly abstracts of all Reports and Memoranda of the Aeronautical Research Council, Technical Reports and Translations of the United States…
Abstract
Under this heading are published regularly abstracts of all Reports and Memoranda of the Aeronautical Research Council, Technical Reports and Translations of the United States National Aeronautics and Space Administration and publications of other similar Research Bodies as issued.
Under this heading are published regularly abstracts of all Reports and Memoranda of the Aeronautical Research Council, Reports and Technical Memoranda of the United States…
Abstract
Under this heading are published regularly abstracts of all Reports and Memoranda of the Aeronautical Research Council, Reports and Technical Memoranda of the United States National Advisory Committee for Aeronautics and publications of other similar Research Bodies as issued.
Under this heading are published regularly abstracts of all Reports and Memoranda of the Aeronautical search Council, Technical Reports and Translations of the United States…
Abstract
Under this heading are published regularly abstracts of all Reports and Memoranda of the Aeronautical search Council, Technical Reports and Translations of the United States National Aeronautics and ace Administration and publications of other similar Research Bodies as issued.
Under this heading are published regularly abstracts of all Reports and Memoranda of the Aeronautical Research Council, Reports and Technical Memoranda of the United States…
Abstract
Under this heading are published regularly abstracts of all Reports and Memoranda of the Aeronautical Research Council, Reports and Technical Memoranda of the United States National Advisory Committee for Aeronautics and publications of other similar Research Bodies as issued.
Ferrante Neri, Xavier del Toro Garcia, Giuseppe L. Cascella and Nadia Salvatore
This paper aims to propose a reliable local search algorithm having steepest descent pivot rule for computationally expensive optimization problems. In particular, an application…
Abstract
Purpose
This paper aims to propose a reliable local search algorithm having steepest descent pivot rule for computationally expensive optimization problems. In particular, an application to the design of Permanent Magnet Synchronous Motor (PMSM) drives is shown.
Design/methodology/approach
A surrogate assisted Hooke‐Jeeves algorithm (SAHJA) is proposed. The SAHJA is a local search algorithm with the structure of the Hooke‐Jeeves algorithm, which employs a local surrogate model dynamically constructed during the exploratory move at each step of the optimization process.
Findings
Several numerical experiments have been designed. These experiments are carried out both on the simulation model (off‐line) and at the actual plant (on‐line). Moreover, the off‐line experiments have been considered in non‐noisy and noisy cases. The numerical results show that use of the SAHJA leads to a saving in terms of computational cost without requiring any extra hardware components.
Originality/value
The surrogate approach in the design of electric drives is novel. In addition, implementation of the proposed surrogate model allows the algorithm not only to reduce computational cost but also to filter noise caused by the sensors and measurement devices.
Details
Keywords
A finite strain measure and a Hookean type finite hyperelastic model based on it were introduced by H. Hencky (1928, 1929) about seventy‐five years ago. About tweenty‐five years…
Abstract
A finite strain measure and a Hookean type finite hyperelastic model based on it were introduced by H. Hencky (1928, 1929) about seventy‐five years ago. About tweenty‐five years later, an objective Eulerian equation of rate form was established by C. Truesdell (1952, 1955) for a rate type extension of Hooke’s law to finite deformations. Originating from these, a history is constantly extending and a tradition is continuing to develop in constitutive modeling of elastic and inelastic behaviour at finite deformations. In a short story consisting of five parts, we would like to relate selected episodes and events in some relevant aspects. Our main objective is to disclose unexpected, perhaps interesting, intrinsic relationships between these independent creations by two great masters and to expound how and why these relationships play essential roles in understanding and clarifying fundamental issues in Eulerian rate theories of finite elastoplasticity
Details
Keywords
The purpose of this paper is to carry out a delamination fracture analysis of the three-dimensional functionally graded split cantilever beam (SCB) configuration.
Abstract
Purpose
The purpose of this paper is to carry out a delamination fracture analysis of the three-dimensional functionally graded split cantilever beam (SCB) configuration.
Design/methodology/approach
The fracture behaviour was studied analytically in terms of the strain energy release rate by applying methods of linear elastic fracture mechanics. It was assumed that the material is functionally graded along the beam width, height and length. The strain energy release rate was derived by analysing the stress and strain state in the beam cross-sections ahead and behind the crack front. An additional analysis of the strain energy release rate was performed by considering the beam strain energy for verification.
Findings
The influence of material gradient along the beam width, height and length on the delamination fracture behaviour was investigated. The effect of crack length was analysed too. The analytical approach developed is very useful for parametric fracture investigations. The results obtained in the present study can be applied for optimisation of three-dimensional functionally graded beam systems in their design with respect to delamination fracture behaviour.
Originality/value
An analytical approach for studying the delamination fracture in the SCB configuration that is functionally graded along the beam width, height and length was developed.