Trampoline Enclosure Safety Engineering Analysis

An 18 month old boy died when he became entrapped in a gap formed between the bottom of a trampoline net safety enclosure and the top of the trampoline structure. Accident statistics survey, safety literature review, standards research, and alternative trampoline safety enclosure design evaluation are approaches utilized in the safety engineering analysis. The primary goal of this investigation is to make trampoline enclosure designers, retailers, customer service providers, and users more aware of the entrapment and strangulation dangers and to identify design alternatives to prevent similar injuries from occurring.

A Comparison of Machine Risk Acceptance Results Among Trained Users of ANSI B11-TR3

The ANSI guideline on machine risk assessment, B11-TR3, describes risk assessment as an iterative process. This implies that protective measures of varied levels of technology can be successively evaluated until a risk that is acceptable is attained. The theories of risk acceptance are many. Reducing risk to a level that is agreed to be 'as low as reasonably practicable' (ALARP) is said to give focus to making a decision about when risk has been adequately reduced. Main (2004) says that "Although the concept of acceptable risk is becoming more commonly adopted throughout the world, a single level of acceptability cannot be universally applied. Acceptable risk is a function of many factors, and is specific to a company, culture, and time-era." Fischhoff et al. (1981) have argued that "the risk associated with the most acceptable option is not acceptable in any absolute sense. One accepts options, not risks, which are only one feature of options." This paper describes risk assessment groups in five manufacturing workplaces and discusses training that led to acceptable risk decisions for a hazardous machine system in each workplace. The composition of the five teams in this study ranged from a team with just a single engineer to teams involving several workplace personnel. The applied preventive measures ranged from measures that were tailored to meet corporate safety goals to measures that evolved from the local risk assessment team's ingenuity. The paper concludes with suggestions on how to make the risk acceptance concept meaningful in the training of future machine risk assessment teams.

Model Uncertainty in Fluid-Structure Impact Risk Analysis

This paper investigates the issue of model uncertainty in risk assessments of fluid-structure impact problems. Model-based risk assessments of complex phenomena such as the space shuttle solid rocket booster (SRB) splashdown event is affected by significant model uncertainty and approximations in finite element discretization, damage modeling, and the probabilistic analysis. Model verification and validation (V&V) helps in systematic assessment of modeling error, and suitable V&V techniques are explored in this paper. Since experimental testing of the SRB is infeasible, a simplified experimental framework is devised using an aluminum cylinder hinged at one end, with the objective of providing insights into the required model form (validation) as well as the required model resolution (verification). Preliminary results from error quantification as well as experimental validation are presented and discussed. Such information could be used to develop confidence and credibility in real-world reliability predictions of fluid-structure impact problems such as SRB splashdown.

Promotion of Technology Commercialization and Local Economy Development by Non-Research-Intensive Universities

In the last 25 years, the research conducted in universities, hospitals, and research institutions has resulted in the creation of over 4500 new companies based on the licenses obtained from these institutions. In the same period, there has been a 1500 percent increase in the number of patents granted to universities. These achievements have been primarily at research universities and research institutions, and have not been enjoyed by the overwhelming majority of educational institutions that are not research-intensive. This paper examines technology commercialization activities at non-research-intensive universities and recommends means by which they can generate more intellectual property in a cost-effective manner. These universities can increase financial opportunities for themselves and their communities and can be more effective in job creation and local economic development by adopting policies that are different from those of their research-intensive counterparts. They can use their resources more creatively to promote creation of intellectual property, faculty entrepreneurship, and interdisciplinary cooperation among faculty

Fire and Explosion Investigations: Why Heavy Trucks May Burn

There is a basic misconception that diesel fuel does not explode and/or ignite upon a collision or impact. This particular chain of events, in fact, does occur. However, it is not always thoroughly investigated or understood. The purpose of this paper, through mechanical analysis and accident reconstruction, is to inform truck manufacturers and operators of this hazard. In addition, it will supply design alternatives that will aid in mitigating and/or preventing injuries altogether.

Reliability Evaluation Using Finite Element Method

A robust and sophisticated structural reliability evaluation procedure is presented. Reliability of any structural systems represented by finite elements can be evaluated using the algorithm. The authors called it a stochastic finite element method. Despite the significant recent progress in the risk and reliability analysis techniques, a large segment of the engineering profession is not familiar with them and thus fails to use them in everyday practices. The procedure is expected to fill that vacuum. Many sources of nonlinearity generally overlooked in the profession can be incorporated in the algorithm. Uncertainties in the load and resistance-related variables are modeled as realistically as possible. The estimation of the failure, probability implies that structural behavior just before failure needs to be captured as accurately as possible. The algorithm is capable of evaluating the probability of failure addressing all the related issues. With the help of four informative examples, the application potential of the procedure is clearly demonstrated. It is similar to the deterministic methods and is not expected to be complicated to the practicing engineers; thus, promoting its wider applications. It is shown that the observations made in laboratory experiments can be explained with the procedure. It is hoped that the method will be used in the future to estimate the reliability of real structures.

Distributed Component Development Risk Analysis

This paper describes a method to identify and to evaluate the risks associated with task transfer in a globally distributed engineering environment. Enterprises realize the importance of global worksharing to include diverse customer values into product, but this paradigm also introduces challenges in product development. Industry-wide interviews reveal workshare risks are at two levels: system and component. This paper presents a three-step risk analysis to 1.) characterize product development work tasks, 2.) define Distributed Component Development Risk based on historical rework data, and 3.) evaluate workshare scenarios for the task transfer plan. Three interior vehicle components illustrate the steps of the risk analysis, and the findings indicate most rework happens at the system-level design stage while the discovery of these errors occurs during validation and manufacturing. As a result, the transfer of these tasks leads to high likelihood of rework. Currently, this method is applying in actual global automotive programs for validations.

Structural Health Assessment After an Impact

An innovative technique to assess structural health just after subjected to impulsive loadings (blasts, explosions, etc.) underdevelopment at the University of Arizona was experimentally verified and is presented in this paper. The authors called it the Generalized Iterative Least Square Extended Kalman Filter with Unknown Input (GILS-EKF-UI) method. The system is represented by finite elements and a Kalman filter-based system identification (SI) technique is used to identify the system. Some of the major characteristics of the method are that it does not require information on input excitation and can identify a system with limited noise-contaminated response information measured at few node points. To implement the Kalman-filter based algorithm, the information on the input excitation and the initial state vector must be available. The authors proposed a two-stage approach. In the first stage, based on the limited measured response information available at the locations of the sensors, a substructure is identified. After the completion of the first stage, the input excitation information that caused the responses and the stiffness of all the elements in the substructure can be evaluated. Then, in stage 2, the Kalman-filter based algorithm is used to identify the whole structure. The experimental verification of the method is emphasized in this paper.

A Risk Based Study of Tipover and Off-Dock Accidents Involving Stand-Up Lift Trucks

It is known that operators of stand-up lift trucks who are involved in either tipover or off-dock accidents are at risk of injury whether they stay within the operator compartment during the accident, are ejected from the operator compartment, or try to jump clear of the falling lift truck. This paper presents the results of a study and analysis of 347 tipover accidents and 192 off-dock accidents involving stand-up lift trucks, all occurring between 1978 and 2002. Tipover accident reports were evaluated with respect to the severity of injury, the action of the operator, and the direction of the lift truck tipover. Off-dock accidents were evaluated with respect to the severity of the injury, the operator action and the direction that the lift truck went off the dock. The results for both tipover and off-dock accidents will be presented to allow comparison between operator action and the severity of tipover to provide designers of stand-up lift trucks with means to best reduce the likelihood of severe injuries or deaths.

Midstream Modulation of Nanotechnology in an Academic Research Laboratory

No clear implementation methods exist for US legislation on integrating societal considerations into nanotechnology research and development. An empirical study was thus undertaken to investigate the possibility and utility of "sociotechnical integration" during nanoscale engineering research in an academic setting. For twelve weeks, an "embedded humanist" interacted with three graduate engineering researchers to identify and assess opportunities for influencing research decisions in accordance with societal concerns. The study focused not on the nature of societal concerns, but on the nature of engineering decisions, and on the potential capacity of researchers to perform integration by "modulating" their decisions. Engineering research decisions were found to be subject to societal influences, and researchers were found to become aware of the possibility of modulating their decisions accordingly. The interactions were not found to hamper research and were found to add value to research. No attempt was made to alter research decisions, only to stimulate awareness of the possibility of doing so. Still, one researcher did alter several decisions as a result of the study. Midstream modulation represents a promising approach for implementing US nanotechnology policy.