Enhancement of Vehicle Safety and Improving Vehicle Yaw Behaviour Due to Offset Collisions Using Vehicle Dynamics

This study aims to optimise Vehicle Dynamic Control Systems (VDCS) in offset impact for vehicle collision mitigation. A proposed unique 3-D full-car mathematical model is developed and solved numerically to carry out this analysis. In this model, vehicle dynamics is studied together with the vehicle crash structural dynamics. Validation of the vehicle crash structure of the proposed model is achieved to ensure that the modelling of the crumple zone and the dynamic responses are reliable. It is demonstrated from the numerical simulations that the vehicle dynamic responses are captured and analysed and the influence of VDCS is determined accurately. In addition, it is shown that the mathematical model is flexible, useful and can be used in optimisation studies

Measuring the alignment of Maintenance and Manufacturing Strategies – The development of a new model and diagnostic tool

Purpose - To outline the development of a new conceptual model and diagnostic tool which assesses the strategic processes and links involved between maintenance and manufacturing strategies and the effect on manufacturing performance. Methodology - The new model was developed in two stages. Firstly a conceptual framework was produced and then a holistic diagram. From this theoretical model a diagnostic tool was generated. This tool was then verified and tested during an empirical research phase which produced four extensive and detailed case studies. A brief overview of one of the case studies is provided in this article. Findings - It was found that the conceptual model provided an accurate representation of the strategic processes and links which should exist in a manufacturing plant. Moreover the diagnostic tool proved to be a valid and reliable test instrument to measure and display this information. Practical implications - The diagnostic tool provides a snapshot of the status of manufacturing and maintenance strategies which then can be used to benchmark improvements over time. If required the individual questions from the questionnaire can be “reverse engineered” to provide detailed information for senior managers to carry out corrective action. Originality/value – This theoretical and empirical research closes a gap in the literature relating to the linkage between maintenance and manufacturing strategies. It does so by providing a unique and holistic model showing the strategic processes and links which should exist within a manufacturing plant. Moreover the diagnostic tool produced from the model is a convenient audit facility which enables companies to move toward functional coherence

Creating and Sustaining a Maintenance Strategy: A Practical Guide

Manufacturing companies should create maintenance strategy and link it to the manufacturing and business goals but recent research in the North East of England suggested that few companies do this. It is unclear why this inertia existed but it could have been due to the complexity and variety of the advice on offer in relation to the formulation and implementation of strategy. The purpose of this paper was to provide a simple generic guide or roadmap for practitioners to follow. It began by highlighting the importance and benefits of a maintenance strategy and then considered literature appropriate to the topic. A key point arising from this review was that the three elements; process, content, context, need to be considered over the lifecycle of a strategy. Moreover, most strategic models converged to simple sequential models affording a generic functional process to be developed. This involved the integration of the “corporate hard systems” model and the “Plan, do, check, act, cycle“, forming a suitable maintenance strategy process. Accordingly, further guidance on policy assured the right “content”. The paper concluded with a short questionnaire used to audit the effect of “contextual factors” on maintenance strategy. The result was a comprehensive guide on how to formulate and implement maintenance strategy

The influence of Vehicle Dynamics Control System on the Occupant’s Dynamic response during a Vehicle collision

This paper aims to apply a vehicle dynamics control system to mitigate a vehicle collision and to study the effects of this systems on the kinematic behaviour of the vehicle's occupant. A unique three-degree-of-freedom vehicle dynamics-crash mathematical model and a simplified lumped-mass occupant model are developed. The first model is used to define the vehicle body's crash parameters and it integrates a vehicle dynamics model with a model of the vehicle's front-end structure. In this model, the anti-lock braking system and the active suspension control system are co-simulated, and the associated equations of motion are developed. The second model aims to predict the effect of the vehicle dynamics control system on the kinematics of the occupant. The Lagrange equations are used to solve that model owing to the complexity of the obtained equations of motion. It is shown from the numerical simulations that the vehicle dynamics-crash response and occupant behaviour can be captured and analysed quickly and accurately. Furthermore, it is shown that the vehicle dynamics control system can affect the crash characteristics positively and that the occupant's behaviour is improved

Towards a Simpler Selection Process for Maintenance Strategies

Recent research at four large manufacturing sites in the North East of England showed that maintenance organisations were failing because they were locked in a cycle of quick fix and mend despite deploying extensive planned maintenance policies. Consequently they were unable to plan and formulate strategies because they did not have the time. Simple and quick tools were needed to select the best maintenance approach for the machines and the plant. Two possible selection tools were developed. Firstly a truth table was produced based on the key characteristics of each maintenance approach and these mapped against simplified failure mode combinations. This offered a quick and easy selection method for machines, based on failure mode patterns. Secondly, the macro level was addressed using a conceptual model employing a 2x2 matrix. This consisted of two axes, the level of machine failures and the level of improvement activity. The resulting framework was used to predict how maintenance organisations would progress from a state of reactive maintenance towards world class. Then informed by the truth table it was possible to select an appropriate maintenance approach which was most suitable for each stage. It is suggested that these two methods offer simple and quick approaches to guide vital maintenance decision making at plants in difficulty. This of course does not preclude the need to develop maintenance strategies but rather facilitates this process by freeing up time and resources

Crash Analysis and Energy Absorption Characteristics of S-shaped Longitudinal Members

This paper presents finite element simulations of the crash behavior and the energy absorption characteristics of thin S-shaped longitudinal members with variable cross-sections made of different materials to investigate the design of optimized energy-absorbing members. Numerical studies are carried out by simulation via the explicit finite element code LS-DYNA [1] to determine the desired variables for the design of energy-absorbing members. The specific energy absorption (SEA), the weight of the members and the peak force responses during the frontal impact are the main measurements of the S-shaped members' performance. Several types of inner stiffening members are also investigated to determine the influence of the additional stiffness on the crash behavior

Alien Registration- Macintyre, John R. (Portland, Cumberland County)

https://digitalmaine.com/alien_docs/22180/thumbnail.jp