Press shop machine analysis and trending

Historically downtime data collection and reporting systems in many automotive body panel press shops has been somewhat adhoc. The impetus for this study stems from frustration in respect of how this data is collected, assessed for trends and presented. Ideally this data should be used to identify costly repetitious faults for actioning of maintenance work and for feedback to tool design for consideration when designing new parts.Presently this data is stored largely in the form of tacit knowledge by press shop operators; the encumbrance of transferring such information being that there is very often only limited channels to quantify it into something more tangible. Findings show that there tend to be two related obstacles to plant data recording. The first is that automation of down time data collection alone cannot determine fault causes as the majority of press shop events are initiated primarily from operator observation. The second is that excessive subjective operator input can often result in confusion and end up taking greater time in recording than remedying the actual fault.This Paper presents the development of a system that through press mounted touchscreens encourages basic subjective operator input and relates this with basic objective data such as timekeeping. In this way all responses for a given press line become valuable and can be trended and placed in a hierarchy based on their percentage contribution to downtime or statistical importance. This then is capable of statistically alerting maintenance, line flow and/or toolbuild areas as to what issues require their most urgent attention.<br /

Development of a new integration algorithm for parallel implementation of the finite element elasto-plastic analysis

The accurate integration of stress-strain relations is an important factor in element analysis for elasto-plastic problems. The conventional method for this problem is the Euler algorithm which divides the whole integration process into a number of smaller substeps of equal size. It is difficult to control the errors in such integration scheme. In this paper, we will present a new algorithm for integrating strain-stress relations. It is based on the third and the fourth order Runge-Kutta method. This substepping scheme controls the errors in the integration process by adjusting the substep size automatically. In order to implement the substepping scheme on parallel systems, a parallel preconditioned conjugate gradient method is developed. The resulting algorithms have been implemented on a parallel environment defined by a cluster of workstation and their performance will be presented

Master planned estates : parish or panacea?

Master planned estates in Australia emerge from two major directions: one aims to address the inadequacies of 1970s suburbanisation and the other comes from governments and developers seeking to realise alternatives. The very idea of master planning has a longer history, one that arguably dates back to 19th-century Utopian Socialism and Baron Haussmann\u27s redesign of Paris, which involved a large-scale, comprehensive alternative vision realised by a sanctioned authority. Master planning thereby partakes of both utopianism and authoritarianism. These associations have infused the discussion and construction of Australian master planned estates rendering them both pariah and panacea. But research and my own experience suggests that they are far more panaceas than pariahs

The effect of clamping sequence on dimensional variability in sheet metal assembly

Finite element (FE) modelling techniques have become a popular tool for exploring welding and clamping sequence dependence in sheet metal assemblies. In the current paper, the dimensional variability associated with different assembly clamping sequences is investigated with a FE contact modelling approach implemented in the commercial code Abaqus. A simplified channel section assembly consisting of a top hat and bottom plate is the case study investigated. Expected variation modes of bow and twist were used to simulate key variability sources in the main structural component under investigation; the top hat of the channel section. It was found that final assembly variability can change considerably depending on clamp sequence selection. It was also found that different clamp sequences can control particular modes of variation better than others, and that there is not one particular clamping sequence that is the best for containing all variation modes. An adaptable assembly process is therefore suggested, where given the shape of input components the best available clamping sequence is selected. Comparison of the performance of the proposed adaptable clamping sequence to traditional fixed clamping sequences shows improvements for the dimensional control of variability in non-rigid components. While introducing such a method in production would require inspection of each component being assembled and investigation of the alternative clamping sequences, given access to fast and detailed dimensional inspection technology such as optical coordinate measuring machines (OCMM\u27s), the approach shows promise for future application. <br /

A methodology for springback prediction

The springback of simple geometries can be predicted through theoretical analysis, however problems arise when transferring this analysis to the manufacturing environment. To determine why this is the case, a studyof small curvature free bending through theoreticalanalysis, manufacturing data and Finite Element (FE)simulation was completed.The theoretical analysis provided an understanding of the behavior of springback and gave accurate predictions in a controlled environment. The manufacturing and Finite Element data verified the trends predicted by theory, but lacked in accuracy. The paper concludes by proposing a prediction method based solely on the geometry that is well defined in both environments.<br /