M. Grujicic, G. Arakere, P. Pisu, B. Ayalew, Norbert Seyr, Marc Erdmann and Jochen Holzleitner
Application of the engineering design optimization methods and tools to the design of automotive body‐in‐white (BIW) structural components made of polymer metal hybrid (PMH…
Abstract
Application of the engineering design optimization methods and tools to the design of automotive body‐in‐white (BIW) structural components made of polymer metal hybrid (PMH) materials is considered. Specifically, the use of topology optimization in identifying the optimal initial designs and the use of size and shape optimization techniques in defining the final designs is discussed. The optimization analyses employed were required to account for the fact that the BIW structural PMH component in question may be subjected to different in‐service loads be designed for stiffness, strength or buckling resistance and that it must be manufacturable using conventional injection over‐molding. The paper demonstrates the use of various engineering tools, i.e. a CAD program to create the solid model of the PMH component, a meshing program to ensure mesh matching across the polymer/metal interfaces, a linear‐static analysis based topology optimization tool to generate an initial design, a nonlinear statics‐based size and shape optimization program to obtained the final design and a mold‐filling simulation tool to validate manufacturability of the PMH component.
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Seteamlak Adane Masresha and Gedefaw Diress Alen
The purpose of this paper is to assess the magnitude of parent-adolescent communication on sexual and reproductive health (SRH) issues and its association with gender and…
Abstract
Purpose
The purpose of this paper is to assess the magnitude of parent-adolescent communication on sexual and reproductive health (SRH) issues and its association with gender and premarital sexual practice among school adolescents of Woldia town.
Design/methodology/approach
School-based cross-sectional study was conducted on 368 unmarried secondary and preparatory school adolescents (15–19 years) in Woldia town. Simple random sampling was employed to select study participants. Self-administered questionnaire was used. Data were entered by EPI-Data version 3.0.2 and analyzed by using SPSS version 20.
Findings
In this study, 56.3% of school adolescents had parental communication on sexual and reproductive health issues. The result of this study showed that adolescents who had history of sexual intercourse where 64% less likely to communicate with parents on sexual and reproductive health issues (AOR: 0.36 95% CI: 0.20, 0.65), but there was no association between gender and sexual and reproductive health communication between adolescent and parent (AOR: 1.06, 95% CI: 0.64, 1.75).
Originality/value
Parent-adolescent communication about sexual matters is one of the means that encourages adolescents to adopt responsible sexual behavior. Many children in Africa are uncomfortable to have a communication about sexual and reproductive health issues with their parents because the subject is a taboo topic in most homes.
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Debraj Das and Debabrata Mukhopadhyay
Volatility in agricultural commodity prices assumes a lot of significance since its associated uncertainty is one of the major factors affecting the income security of producers…
Abstract
Volatility in agricultural commodity prices assumes a lot of significance since its associated uncertainty is one of the major factors affecting the income security of producers and traders. The study aims to investigate the fluctuations and instability of the two crops, paddy and wheat, in the states of India. It has estimated instability in prices over the years (2006–2023) for paddy and wheat for the top three producing states by using coefficient of variation (CV), Cuddy-Della Valle index and Coppock’s index. Then it estimates volatility by generalized autoregressive conditional heteroskedasticity (GARCH) framework. It is observed that the average standard deviation of prices across mandis for paddy in a given month is 0.18 and for wheat it is 0.22. Both for paddy and wheat Punjab has the maximum instability among the three states if we consider CV and Coppock’s index. But if we consider the Cuddy-Della Valle index, Madhya Pradesh has the maximum instability for wheat. The noticed unpredictability in the price series of paddy revealed that the value of ARCH (α) has significant term and value of GARCH (β) was also significant for all the price series. The volatility (α + β) was quite persistent of the order of 0.985 in case of Uttar Pradesh. In case of wheat Punjab has the maximum value 0.95 signifying explosiveness. In case of wheat Punjab has the maximum value 0.95 signifying explosiveness.
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M. Grujicic, G. Arakere, V. Sellappan, J.C. Ziegert and D. Schmueser
Among various efforts pursued to produce fuel efficient vehicles, light weight engineering (i.e. the use of low‐density structurally‐efficient materials, the application of…
Abstract
Among various efforts pursued to produce fuel efficient vehicles, light weight engineering (i.e. the use of low‐density structurally‐efficient materials, the application of advanced manufacturing and joining technologies and the design of highly‐integrated, multi‐functional components/sub‐assemblies) plays a prominent role. In the present work, a multi‐disciplinary design optimization methodology has been presented and subsequently applied to the development of a light composite vehicle door (more specifically, to an inner door panel). The door design has been optimized with respect to its weight while meeting the requirements /constraints pertaining to the structural and NVH performances, crashworthiness, durability and manufacturability. In the optimization procedure, the number and orientation of the composite plies, the local laminate thickness and the shape of different door panel segments (each characterized by a given composite‐lay‐up architecture and uniform ply thicknesses) are used as design variables. The methodology developed in the present work is subsequently used to carry out weight optimization of the front door on Ford Taurus, model year 2001. The emphasis in the present work is placed on highlighting the scientific and engineering issues accompanying multidisciplinary design optimization and less on the outcome of the optimization analysis and the computational resources/architecture needed to support such activity.
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Shilpa Bhaskar Mujumdar, Haridas Acharya and Shailaja Shirwaikar
This paper utilizes data mining to study the effect of Problem Based Learning (PBL), an innovative pedagogical approach that has been implemented in undergraduate education at a…
Abstract
Purpose
This paper utilizes data mining to study the effect of Problem Based Learning (PBL), an innovative pedagogical approach that has been implemented in undergraduate education at a private university in India for teaching Statistics and Operations Research (OR) to techno-management students.
Design/methodology/approach
The study follows the assumptions of an in-situ experiment. It employs BBA (IT) and BCA student(s) as a subject and their end of semester GPA as a performance indicator. The pedagogical approach to this study is integrating PBL with classroom teaching. The paper uses a combination of statistics and data mining to analyze the impact of PBL and establish research conclusions.
Findings
The study concludes that the introduction of PBL positively results in an improved GPA for students with a math background. PBL is more effective for BBA (IT) male students. Female students seem to be performing equally well irrespective of the inclusion of PBL. Pattern analysis of shape parameters evidences the impact of PBL, and the results are established through the decision tree and test of proportions.
Research limitations/implications
The study is limited to students from a single institute.
Practical implications
This Pattern analysis, as applied in this paper, can be scaled to evaluate the impact of any innovative pedagogical approach agnostic of the field of study. Facilitators can use the process defined in the paper to implement PBL for teaching Statistics and Operations research. Shape parameters of the batch in the previous semester can be utilized by facilitators to plan remedial action for the next semester by classifying students as desirable/non-desirable. Techno-management institutes can alleviate the dread and fear of mathematical subjects by integrating PBL with classroom teaching.
Originality/value
The study utilizes an innovative analytical approach of combining shape parameters with classification. It further provides uniqueness in arriving at a classification of batch performance as desirable/non-desirable and utilizes data mining to emphasize a delineating impact of PBL across both critical parameters of the batch and the student. The study also defines a framework for the implementation of PBL for a techno-management program in Statistics and Operations Research.
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Misraku Molla Ayalew and Joseph H. Zhang
The purpose of this paper is to examine the effect of the financial structure on innovation.
Abstract
Purpose
The purpose of this paper is to examine the effect of the financial structure on innovation.
Design/methodology/approach
We utilize the matched firm-level data from two sources: the World Bank Enterprise Survey and the Innovation Follow-Up Survey. A total of 3,664 firms from 11 African countries are included.
Findings
The authors find a financially constrained and low technology-intensive firm that uses internal finance more than its peers is less likely to innovate. Our results also show that a firm that uses new equity and debt finance more than its peers is more likely to innovate. The results particularly suggest the significant effect of bank and trade credit finance on firms’ innovation. The extent and, in some cases, the direction of the effect of dependence on internal finance, new equity finance and debt finance on innovation vary due to the heterogeneity in firm size, age and ownership status. Corporate innovation is also associated with firm size, R&D, cooperation, staff training, public support, exportation and group membership.
Practical implications
The management of companies, particularly financially constrained firms, should reduce their dependence on internal finance, which negatively affects their innovation. As a remedy, they could improve their reliance on new equity finance and debt finance, especially bank finance and trade credit finance, which positively affect their innovativeness.
Social implications
A pending policy task for African business leaders is to design and evaluate reforms that help create strong financial sectors willing to provide capital to a broad range of firms, particularly small and young firms.
Originality/value
This study adds new evidence to the recent surge of debate on the trade-off between going public, using debt or heavily using internal sources to finance innovative projects, and which of these is more important in promoting firm-level innovation.
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Lifeng Wang, Haiqi Wu, Long Liu and Ziwang Xiao
The application of ultra-high performance concrete (UHPC) in anchorage zones can significantly improve the local compression performance of structures. However, the high cost and…
Abstract
Purpose
The application of ultra-high performance concrete (UHPC) in anchorage zones can significantly improve the local compression performance of structures. However, the high cost and complex preparation of UHPC make UHPC difficult to be widely used in practice. This study proposes a method to strengthen the local compression zone of structures built by normal strength concrete (NSC) by incorporating UHPC cores.
Design/methodology/approach
In this study, a Finite Element Model (FEM) of local compression specimens was established by ABAQUS, and the accuracy of FEM was verified by comparing the FEM calculation results with experimental results. The verified FEM was adapted to the research on the influences of affecting factors on local compression performance of structures, including NSC strength, UHPC strength, spiral steel bar strength, and UHPC core diameter.
Findings
The results show that the peak load of the strengthened specimen SC1-U + N increases by 210.2% compared to that of the SC1-NSC. Furthermore, compared to SC1, the strengthened specimen SC1-U + N can save 64.7% amount of UHPC while the peak load decreases by only 34.4%. The peak load of the strengthened specimens increases with the axial compressive strength and the diameter of UHPC cores increasing, crack load increases with increasing the compressive strength of NSC, the spiral steel bar with high strength can prevent the sharp drop of load-deflection curve and the residual bearing capacity increases accordingly. All findings indicate that increasing the diameter of UHPC cores can improve the overall performance of the specimens. Under loading, all specimens fail by following a similar pattern. The effectiveness of this new strengthen method is also verified by FEM analytical calculations.
Originality/value
Based on the experimental study, this study extrapolates the influence of different parameters on the local bearing capacity of the strengthened specimens by finite element simulation. This method not only ensures the accuracy of bearing capacity assessment, but also does not require many samples, which ensures the economy of the reinforcement process. The research results provide a reference for the reinforcement design of anchorage zone.
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M. Grujicic, S. Ramaswami, J.S. Snipes, R. Galgalikar, V. Chenna and R. Yavari
Wind energy is one of the most promising and the fastest growing alternative-energy production technologies, which have been developed in response to stricter environmental…
Abstract
Purpose
Wind energy is one of the most promising and the fastest growing alternative-energy production technologies, which have been developed in response to stricter environmental regulations, the depletion of fossil-fuel reserves, and the world's ever-growing energy needs. This form of alternative energy is projected to provide 20 percent of the US energy needs by 2030. For economic reasons, wind turbines (articulated structures that convert wind energy into electrical energy) are expected to operate, with only regular maintenance, for at least 20 years. However, some key wind turbine components (especially the gearbox) tend to wear down, malfunction and fail in a significantly shorter time, often three to five years after installation, causing an increase in the wind-energy cost and in the cost of ownership of the wind turbine. Clearly, to overcome this problem, a significant increase in long-term gearbox reliability needs to be achieved.
Design/methodology/approach
While purely empirical efforts aimed at identifying shortcomings in the current design of the gearboxes are of critical importance, the present work demonstrates that the use of advanced computational engineering analyses, like the finite-element stress analysis and a post-processing fatigue-life assessment analysis, can also be highly beneficial.
Findings
The results obtained in the present work clearly revealed how a variety of normal operating and extreme wind-loading conditions can influence the service-life of a wind-turbine gearbox in the case when the service-life is controlled by the gear-tooth bending-fatigue.
Originality/value
The present work attempts to make a contribution to the resolution of an important problem related to premature-failure and inferior reliability of wind-turbine gearboxes.
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Annada Prasad Moharana, Ratnesh Raj and Amit Rai Dixit
The industrial application of continuous glass fabric-reinforced polymer composites (GFRPCs) is growing; however, the manufacturing boundedness of complex structures and the high…
Abstract
Purpose
The industrial application of continuous glass fabric-reinforced polymer composites (GFRPCs) is growing; however, the manufacturing boundedness of complex structures and the high cost of molds restrict their use. This research proposes a three-dimensional (3 D) printing process for GFRPCs that allows low-cost and rapid fabrication of complex composite parts.
Design/methodology/approach
The composite is manufactured using a digital light processing (DLP) based Vat-photopolymerization (VPP) process. For the composites, suitable resin material and glass fabrics are chosen based on their strength, stiffness, and printability. Jacob's working curve characterizes the curing parameters for adequate adhesion between the matrix and fabrics. The tensile and flexural properties were examined using UTM. The fabric distribution and compactness of the cured resin were analyzed in scanning electron microscopy.
Findings
The result showed that the object could print at a glass fabric content of 40 volume%. In DLP-based VPP printing technology, the adequate exposure time was found to be 30 seconds for making a GFRPC. The tensile strength and Young's modulus values were increased by 5.54 and 8.81 times, respectively than non-reinforced cured specimens. The flexural strength and modulus were also effectively increased to 2.8 and 3 times more than the neat specimens. In addition, the process is found to help fabricate the functional component.
Originality/value
The experimental procedure to fabricate GFRPC specimens through DLP-based AM is a spectacular experimental approach.
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Lucas Willian Aguiar Mattias and Leilson Joaquim Araujo
This study aims to optimize the structural design of reinforced concrete columns with variable hollow circular sections.
Abstract
Purpose
This study aims to optimize the structural design of reinforced concrete columns with variable hollow circular sections.
Design/methodology/approach
The columns were optimized according to the criteria of instability (buckling) and mechanical strength (compression and/or tensile strength). To perform the optimizations, routines are developed in Python using the penalty and sequential linearization programming (SLP) function methods to optimize the elements satisfying the buckling and stress criteria.
Findings
At the end of the optimization process, the optimal section is obtained for the example of a circular column with a variable section, this section has an average radius of 5% smaller than that initially defined.
Originality/value
The theoretical basis for column optimization and the structuring of an algorithm in Python language for the computational resolution of these problems are presented in a didactic way, as well as the comparative efficiency of the methods.