S.R. Mannava, Sagar Bhamare, Vibhor Chaswal, Leonora Felon, David Kirschman, David Lahrman, Richard Tenaglia, Dong Qian and Vijay Vasudevan
The current industry standard rigid spinal implants suffer fatigue failures due to bending and torsion loads. The purpose of this program was to design novel prototype flexible…
Abstract
Purpose
The current industry standard rigid spinal implants suffer fatigue failures due to bending and torsion loads. The purpose of this program was to design novel prototype flexible titanium alloy spinal implant rod with machined features, and then apply the laser shock peening (LSP) process to restore the fatigue strength debit due to these features.
Design/methodology/approach
A flexible prototype rod was designed with flat section at the center of the rod. The flat section was laser shock peened. Static compression tests were conducted as per American Society of Testing Materials standards for three‐ and four‐point bending tests and “vertebrectomy” constructs. Finite element models were developed to aid in the design of LSP and also to guide the experiments.
Findings
The test results indicated a ∼3X improvement in flexibility and a reduction in fatigue load ratio, defined as applied load divided by the yield load; from 72 to 68 percent. This rod was LSP's on the flat sections, and tested again. The results indicated an increase in the fatigue load ratio from 68 to 75 percent without any further change in flexibility.
Originality/value
It has been demonstrated successfully that the current industry rigid spinal implant rod can be modified for flexibility and laser shock peened to increase fatigue strength. This enhancement will enable the use of the implant for longer periods and higher loads; and for surgical processes with and without fusion. This technology can be readily applied to all metals that are certified for human implant applications; thus can be implemented with minimal clinical trials.
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Pandimani, Markandeya Raju Ponnada and Yesuratnam Geddada
This study aims to present comprehensive nonlinear material modelling techniques and simulations of reinforced concrete (RC) beams subjected to short-term monotonic static load…
Abstract
Purpose
This study aims to present comprehensive nonlinear material modelling techniques and simulations of reinforced concrete (RC) beams subjected to short-term monotonic static load using the robust and reliable general-purpose finite element (FE) software ANSYS. A parametric study is carried out to analyse the flexural and ductility behaviour of RC beams under various influencing parameters.
Design/methodology/approach
To develop and validate the numerical FE models, a total of four experimentally tested simply supported RC beams are taken from the available literature and two beams are selected from each author. The concrete, steel reinforcements, bond-slip mechanism, loading and supporting plates are modelled using SOLID65, LINK180, COMBIN39 and SOLID185 elements, respectively. The validated models are then used to conduct parametric FE analysis to investigate the effect of concrete compressive strength, percentage of tensile reinforcement, compression reinforcement ratio, transverse shear reinforcement, bond-slip mechanism, concrete compressive stress-strain constitutive models, beam symmetry and varying overall depth of beam on the ultimate load-carrying capacity and ductility behaviour of RC beams.
Findings
The developed three-dimensional FE models can able to capture the load and midspan deflections at critical points, the accurate yield point of steel reinforcements, the formation of initial and progressive concrete crack patterns and the complete load-deflection curves of RC beams up to ultimate failure. From the numerical results, it can be concluded that the FE model considering the bond-slip effect with Thorenfeldt’s concrete compressive stress-strain model exhibits a better correlation with the experimental data.
Originality/value
The ultimate load and deflection results of validated FE models show a maximum deviation of less than 10% and 15%, respectively, as compared to the experimental results. The developed model is also capable of capturing concrete failure modes accurately. Overall, the FE analysis results were found quite acceptable and compared well with the experimental data at all loading stages. It is suggested that the proposed FE model is a practical and reliable tool for analyzing the flexural behaviour of RC members and can be used for performing parametric studies.
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Pandimani, Markandeya Raju Ponnada and Yesuratnam Geddada
This paper aims to present nonlinear numerical simulations using the versatile finite element (FE) analysis tool ANSYS and theoretical analysis based on code provisions to assess…
Abstract
Purpose
This paper aims to present nonlinear numerical simulations using the versatile finite element (FE) analysis tool ANSYS and theoretical analysis based on code provisions to assess the load-carrying capacity of reinforced concrete (RC) beams under two-point monotonic static loadings.
Design/methodology/approach
Four quarter-size FE models with load and geometry symmetry conditions were constructed, the load-bearing capacity and associated mid-span deflections at critical points are verified against the full-scale experimental RC beams available in the literature. These developed FE models incorporated the tension stiffening effects and bond–slip behaviour. Theoretical analyses based on Indian standard code IS: 456–2000 and ACI 318–19 were also carried to verify the experimental and numerical predicted moments at critical loading points.
Findings
The load-deflection curves predicted through FE models exhibit closer corroboration with the experimental curves throughout the loading history. The contour plots for deflections, concrete principal stresses, reinforcement yield stresses are satisfactorily predicted by the FE models, which reveal the complete information of nonlinear behaviour of RC beams. The developed model well captured the initial and progressive crack patterns at each load increments.
Practical implications
The FE modelling is an efficient, valid and economical tool that is an alternative to the expensive experimental program and can be used to explore, analyse and fully understand the nonlinear response of RC beams under static loadings.
Originality/value
The ultimate moment capacity evaluated based on ACI 318–19 code provision show a better correlation with the experimental data as compared to the IS: 456–2000 code provision. The ultimate loads and associated centre-span deflections predicted by RN-2, RN-3, RB-12 and RB-16 FE model show a discrepancy of 1.66 and –0.49%, –4.68 and –0.60%, –9.38 and –14.53% and –4.37 and 4.21%, respectively, against the experimental results, which reveals that the developed ANSYS FE models predict consistent results and achieved a reasonable agreement with the experimental data.
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The purpose of this paper is to develop a cross-cultural scale of customers’ perceived switching costs (PSCs). Customers’ PSCs function as a powerful defensive marketing tool that…
Abstract
Purpose
The purpose of this paper is to develop a cross-cultural scale of customers’ perceived switching costs (PSCs). Customers’ PSCs function as a powerful defensive marketing tool that restrains customers from switching.
Design/methodology/approach
Four sets of survey data were collected in the UK, Egypt, Germany, and China. An overall response rate of 86 percent was achieved across the four countries. Cross-cultural equivalence of the PSCs scale was assessed using multi-group confirmatory factor analysis.
Findings
Tests of configural, metric, and factor variance invariance confirmed that the PSCs scale is appropriate for meaningful cross-cultural comparisons.
Research limitations/implications
Data were collected in four countries from the financial service context. Future researchers should test the short-form PSCs (PSCs-S) scale across different cultural and industrial contexts to enhance its generalizability.
Practical implications
The cross-cultural PSCs-S scale presented here will enhance international marketing researchers’ ability to test theory containing customers’ PSCs as central variables, and provide managers with a measurement tool that they can use to better segment and manage their customers.
Originality/value
This study is one of the first to develop a cross-cultural PSCs scale. Despite the growth of research into customers’ PSCs, research on the topic has been limited by the lack of a cross-cultural measurement instrument. The latter now furnishes the research community with the opportunity to gain a fuller understanding of switching behavior, to establish the scale's generalizability, and to make meaningful comparisons of PSCs across cultures.
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Bharat Arora and Zillur Rahman
The purpose of this paper is to examine the impact of superior IT capability on financial performance of firms in the chemicals and chemical products industry in India.
Abstract
Purpose
The purpose of this paper is to examine the impact of superior IT capability on financial performance of firms in the chemicals and chemical products industry in India.
Design/methodology/approach
Financial performance of 28 firms with superior IT capability has been compared with benchmark over a period of six years.
Findings
This research has five important findings for the chemicals and chemical products industry in India: there is positive association between superior IT capability and return on sales (ROS); firms with superior IT capability are able to earn higher margins on their products; asset turn of firms with superior IT capability is less than benchmark; capital markets give higher valuation to firms with superior IT capability; and this superior performance in terms of better ROS and higher capital market valuation is sustainable over a period of time.
Originality/value
This is the first empirical study that has analysed the influence of IT capability on financial performance of firms in a specific industry in the context of India.
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Previous research showed that there are payoffs from IT investments, but the question is when and why such payoffs occur. This paper aims to adopt an “inside the black‐box”…
Abstract
Purpose
Previous research showed that there are payoffs from IT investments, but the question is when and why such payoffs occur. This paper aims to adopt an “inside the black‐box” approach to the analysis of economic benefits of ERP systems by examining what business process (BP) changes take place in companies that have different motives for implementing ERP systems. This explorative study seeks to further examine the influence of these BP changes on organizational performance.
Design/methodology/approach
In Spring 2006, 14 semi‐structured interviews were made in mid‐sized Finnish companies that use an ERP system. An ERP scorecard framework was applied to assess the perceived benefits of ERP.
Findings
Companies that have a technologically‐led motivation perceive “improved service time in accounting tasks” as an internal efficiency benefit, “faster response to business change” as customer benefits, and financial benefits in terms of other improved efficiencies. Companies that have a business‐led motivation perceive “economies of scale” as an internal efficiency benefit, and financial benefits in terms of “lower headcount costs” and “lower selling, general and administrative costs.” Both groups of companies report BP changes in terms of “reassignment of financial management of business cases.”
Research limitations/implications
The balanced‐scorecard approach offers a systematic analysis of the ERP effects in organizations, but it limits the interpretation of the interview data. The small number of ERP implementations studied means that the results are not directly generalizable, but they point out interesting avenues for future research.
Practical implications
The insights in the paper about the relationship between how ERP projects are motivated and how benefits are perceived may be helpful to organizations that implement ERP systems. The findings support the importance of continued monitoring of ERP systems to leverage their effects in maximizing benefits for the implementing organizations.
Originality/value
The paper provides new insights into the interrelationships between the motivations for implementing ERP systems and the perceived ERP benefits.