Summary and Purpose
The purpose of this article was to explore the impacts of human jumping and bobbing forces on slender and flexible structures. The study relies on previous test to evaluate the impacts of damping and structural mass on slender and flexible stadia. The article argues that dynamic forces exerted by the human beings on stadia inform the decisions of the engineers in designing and constructing structures (Harrison, Yao, Wright, Pavic, and Reynolds, 2008). The authors of this article note that human beings are attributable to dynamic forces that cause resonant force. The article recommends that engineers should construct structures that can withstand the resonant energy.
Statement of the Problem
The statement of the problem in this article is that engineers and architects have continued to compromise the mechanical strength of stadia by considering the cost of constructing a structure, aesthetic value, and efficient lead when erecting of the slender structure. According to the article, the ignorance is detrimental to the safety of the stadia.
Significance of the Study
The study sought to inform the architects and engineers on the importance of constructing strong structures. The flexible and slender structures compromise human safety. It is imperative to incorporate the study findings in the design of the structures such as stadia.
Methodology
The current study relied on the previous studies to establish the relationship between “platform natural frequency and the prop position” (2008). The investigators employed modal test using the electro-dynamic shaker and instrumented hammer. Consequently, the researchers adjusted the ratio of subject and structure to that of damping to determine the resonance structure effect. The results of the experiment were calculated using an analytical model that incorporates loading capacity, especially on unoccupied stadia terraces. Similarly, the study calculated the response of the structure to crowd induced movements.
Findings
The findings indicate, “Degree of force dropout tends to reduce when human beings bob or jump near to resonance” (2008). The results show that it is impossible to reach the natural frequencies of the platform used to represent the flexible structure. In essence, the decrease in resonance amplitude allows subjects to maintain activity at an equivalent frequency to that of the flexible structure (2008). The conclusion of the research was that effect of the subject jumping at half the natural frequency of the structure was similar to that of the crowd’s first harmonic force.
Importance of Article
The article is important in my field of interest because it shows that proper designing of structures is important to avoid destructive effects. In addition, the article forms a strong foundation for the establishment of the gaps, which the previous researches have not investigated. Therefore, the study my research will use the study as part of the literature review.
Critique
The article relied heavily on the previous studies. In addition, the researchers did not relate their research to the current used in the design of the structures. Therefore, the study overlooked the central components to the design of the structure. Moreover, the study used both the active and passive participants. It would have been better if the researchers focused on either active or passive participation instead of using the two simultaneously. Similarly, the author does not mention any limitations of the study. Limitation is a crucial part in a research. The acknowledgement of the limitation in research allows the readers to understand the results. In addition, the limitations give the researchers an opportunity to suggest an approach for future research.
Reference
Harrison, E., Yao, S., Wright, J., Pavic, A., & Reynolds, P. (2008). Human jumping and bobbing forces on flexible structures: Effect of structural properties. Journal of Engineering Mechanics, 134 (8), 663-677.