Paulo J Tavares, Tiago Ramos, Daniel Braga, Mario A P Vaz and Pedro Miguel Guimarães Pires Moreira
Hybrid methods, wherefore numerical and experimental data are used to calculate a critical parameter, have been used for several years with great success in Experimental Mechanics…
Abstract
Purpose
Hybrid methods, wherefore numerical and experimental data are used to calculate a critical parameter, have been used for several years with great success in Experimental Mechanics and, in particular, in fracture mechanics. The purpose of this paper is to report on the comparison of the strain field from numerical modelling forecasts against the experimental data obtained with the digital image correlation method under Mode II loading in fatigue testing. The numerical dual boundary element method has been established in the past as a very reliable method near singular regions where stresses tend to grow abruptly. The results obtained from the strain data near the crack tip were used in Williams expansion and agree fairly well with both the numerical results and the analytical solution proposed for pure Mode II testing.
Design/methodology/approach
The work presented in this note is experimental. The proposed methodology is of an hybrid experimental/numerical nature in that a numerical stress intensity factor calculation hinges upon a stress field obtained with an image method.
Findings
The obtained results are an important step towards the development of a practical tool for crack behaviour prediction in fatigue dominated events.
Research limitations/implications
The results also stress the necessity of improving the experimental techniques to a point where the methods can be applied in real-life solicitations outside of laboratory premises.
Originality/value
Although several research teams around the globe are presently working in this field, the present research topic is original and the proposed methodology has been presented initially by the research team years ago.
Details
Keywords
Tom Schultheiss, Lorraine Hartline, Jean Mandeberg, Pam Petrich and Sue Stern
The following classified, annotated list of titles is intended to provide reference librarians with a current checklist of new reference books, and is designed to supplement the…
Abstract
The following classified, annotated list of titles is intended to provide reference librarians with a current checklist of new reference books, and is designed to supplement the RSR review column, “Recent Reference Books,” by Frances Neel Cheney. “Reference Books in Print” includes all additional books received prior to the inclusion deadline established for this issue. Appearance in this column does not preclude a later review in RSR. Publishers are urged to send a copy of all new reference books directly to RSR as soon as published, for immediate listing in “Reference Books in Print.” Reference books with imprints older than two years will not be included (with the exception of current reprints or older books newly acquired for distribution by another publisher). The column shall also occasionally include library science or other library related publications of other than a reference character.
Nada K. Kakabadse, Hong Yang and Richard Sanders
The primary aim of this paper is to examine whether boards of directors with independent members function as effective corporate governance mechanisms in Chinese State‐Owned…
Abstract
Purpose
The primary aim of this paper is to examine whether boards of directors with independent members function as effective corporate governance mechanisms in Chinese State‐Owned Enterprises (SOEs), by analysing four characteristics of non‐executive directors (NEDs) that impact on their effectiveness, namely their degree of independence, information, incentive, and competence.
Design/methodology/approach
Being exploratory in nature, the research uses qualitative methods for data collection. It is based on an interpretivist perspective of social sciences, analysing and explaining the factors that influence the effectiveness of NEDs.
Findings
The findings indicate that the NED system is weak in China as a result of the concentrated ownership structure, unique business culture, intervention of controlling shareholders and the lack of understanding of the benefits brought by NEDs.
Research limitations/implications
The paper examines the salient features of and challenges to the system of NEDs of SOEs in present‐day China. It provides an understanding of how the various perceptions of the board, gathered from in‐depth interviews of corporate directors, leads to new interpretations of board effectiveness. The research, however, is limited owing to a relatively small sample size and the sensitive nature of the information collected.
Originality/value
The study aims to fill gaps in the literature and contribute to it by assessing the “real” views and perceptions of NEDs in China in an institutional environment significantly different from that of the USA, the UK and other western economies.
Details
Keywords
Fariss‐Terry Mousa and William Wales
This paper aims to explore the effects of entrepreneurial orientation (EO) on firm survival and examine whether founder chief executive officers (CEOs) are more effective than…
Abstract
Purpose
This paper aims to explore the effects of entrepreneurial orientation (EO) on firm survival and examine whether founder chief executive officers (CEOs) are more effective than other types of managers at utilizing entrepreneurial orientation at initial public offerings (IPOs).
Design/methodology/approach
Using survival analysis the authors investigate the effects of EO on firm survival as well as the moderating role of founder CEOs.
Findings
The results suggest that EO increases post‐IPO survival. Further, founder‐CEOs moderate the EO‐survival relationship.
Originality/value
The paper shows that entrepreneurial orientation enhances long‐term survival in IPO firms. Survival is an important, though generally overlooked consideration in EO research. The paper also concludes that firms with founder CEOs are more likely to value and implement EO. Finally, the paper addresses calls for greater use of secondary measures of EO.
Details
Keywords
THOMAS Carlyle's personal crusade for the opening of a lending library in London and his enlisting for the support of that cause influential and wealthy patrons such as Lord…
Abstract
THOMAS Carlyle's personal crusade for the opening of a lending library in London and his enlisting for the support of that cause influential and wealthy patrons such as Lord Clarendon, Bulwer‐Lytton, Lord Lyttelton, Dean Milman, Lord Houghton, W. E. Gladstone, Sir G. Cornewall Lewis, Henry Hallam—amongst a host of other now forgotten early Victorian luminaries—is well documented. According to Robert Harrison's Preface to the 1888 fifth edition of the Catalogue of the London Library, it opened on 3 May 1841 “with a collection of about 3,000 volumes, which, by the following March, when the first Catalogue was published, had increased to 13,000” (p.viii). The Library was declared formally open on 24 May 1841 using a hired hall in Pall Mall. There were 500 members. In April 1845 the Library moved to its present location in St. James's Square.
The purpose of this paper is to propose the new dependences of cycles to failure for a given initial crack length upon the stress amplitude in the linear fracture approach. The…
Abstract
Purpose
The purpose of this paper is to propose the new dependences of cycles to failure for a given initial crack length upon the stress amplitude in the linear fracture approach. The anticipated unified propagation function describes the infinitesimal crack-length growths per increasing number of load cycles, supposing that the load ratio remains constant over the load history. Two unification functions with different number of fitting parameters are proposed. On one hand, the closed-form analytical solutions facilitate the universal fitting of the constants of the fatigue law over all stages of fatigue. On the other hand, the closed-form solution eases the application of the fatigue law, because the solution of nonlinear differential equation turns out to be dispensable. The main advantage of the proposed functions is the possibility of having closed-form analytical solutions for the unified crack growth law. Moreover, the mean stress dependence is the immediate consequence of the proposed law. The corresponding formulas for crack length over the number of cycles are derived.
Design/methodology/approach
In this paper, the method of representation of crack propagation functions through appropriate elementary functions is employed. The choice of the elementary functions is motivated by the phenomenological data and covers a broad region of possible parameters. With the introduced crack propagation functions, differential equations describing the crack propagation are solved rigorously.
Findings
The resulting closed-form solutions allow the evaluation of crack propagation histories on one hand, and the effects of stress ratio on crack propagation on the other hand. The explicit formulas for crack length over the number of cycles are derived.
Research limitations/implications
In this paper, linear fracture mechanics approach is assumed.
Practical implications
Shortening of evaluation time for fatigue crack growth. Simplification of the computer codes due to the elimination of solution of differential equation. Standardization of experiments for crack growth.
Originality/value
This paper introduces the closed-form analytical expression for crack length over number of cycles. The new function that expresses the damage growth per cycle is also introduced. This function allows closed-form analytical solution for crack length. The solution expresses the number of cycles to failure as the function of the initial size of the crack and eliminates the solution of the nonlinear ordinary differential equation of the first order. The different common expressions, which account for the influence of the stress ratio, are immediately applicable.
Details
Keywords
David Anthony Kirby and Iman El-Kaffass
The article is intended to consider how entrepreneurship needs to adapt if it is to address the global sustainability challenge. The intention is to propose a new business model…
Abstract
Purpose
The article is intended to consider how entrepreneurship needs to adapt if it is to address the global sustainability challenge. The intention is to propose a new business model that recognises the interconnectedness of the global ecosystem.
Design/methodology/approach
The article analyses two case studies purposively written to demonstrate the difference between the traditional entrepreneurship approach, dating back to the 19th century and the proposed harmonised one. Both cases are based on secondary data and personal field observation.
Findings
While the two cases focus on wealth creation, job generation and innovation, the traditional approach is shown to have had a long-term deleterious impact on both society and the environment, whereas the proposed harmonised approach impacts positively. The article recognises the multifaceted nature of the sustainability challenge and that the three elements (economy/commerce, society and environment) are interconnected. If there is a change in the status of one the other, connected facets will change or will need to be changed. Thus any solution needs to address all three facets.
Social implications
The proposed business model will be of interest to scholars and practitioners of entrepreneurship and sustainability, as well as to policy makers and educators.
Originality/value
Apart from proposing a new business model that will address the sustainability challenge, the article provides a definition of harmonious entrepreneurship and identifies the conditions required for it to be met, as well as the characteristics of the harmonious entrepreneur.