Design Spectrum Analysis in NASTRAN

The utility of Design Spectrum Analysis is to give a mode by mode characterization of the behavior of a design under a given loading. The theory of design spectrum is discussed after operations are explained. User instructions are taken up here in three parts: Transient Preface, Maximum Envelope Spectrum, and RMS Average Spectrum followed by a Summary Table. A single DMAP ALTER packet will provide for all parts of the design spectrum operations. The starting point for getting a modal break-down of the response to acceleration loading is the Modal Transient rigid format. After eigenvalue extraction, modal vectors need to be isolated in the full set of physical coordinates (P-sized as opposed to the D-sized vectors in RF 12). After integration for transient response the results are scanned over the solution time interval for the peak values and for the times that they occur. A module called SCAN was written to do this job, that organizes these maxima into a diagonal output matrix. The maximum amplifier in each mode is applied to the eigenvector of each mode which then reveals the maximum displacements, stresses, forces and boundary reactions that the structure will experience for a load history, mode by mode. The standard NASTRAN output processors have been modified for this task. It is required that modes be normalized to mass

Experience with Free Bodies

Some of the problems that confront an analyst in free body modeling, to satisfy rigid body conditions are discussed and with some remedies for these problems are presented. The problems of detecting these culprits at various levels within the analysis are examined. A new method within NASTRAN for checking the model for defects very early in the analysis without requiring the analyst to bear the expense of an eigenvalue analysis before discovering these defects is outlined

Understanding digital eco-innovation in municipalities: An institutional perspective

Municipalities consume over 67% of global energy and are responsible for over 70% of greenhouse gas emissions (GHG). The Intergovernmental Panel on Climate Change warns that rapid adjustments need to happen at a global level, or the effects of climate change will be irreversible. The contribution of municipalities is therefore vital if GHG emissions are to be reduced. Our research is timely in its exploration of the ways in which municipalities institutionalise environmental sustainability practices in and through Green digital artefacts. Using mechanism-based institutional theory as a lens, the paper presents the findings of three contrasting case studies of large municipalities in the United Kingdom in their respective programmes to leverage the direct, enabling and systemic effects of Green ICT in order to reduce GHG emission and achieve their eco-sustainability goals. The case sites are also regarded as exemplars for further research and practice on digital eco-innovation. The mechanism-based explanations illustrate how a social web of conditions and factors influence eco-sustainability outcomes. We conclude that the digital technology-enabled grassroots-based initiatives offer the best hope to begin the transition to sustainable climate change within municipalities. The contributions of our study are therefore both theoretical and practical

Organic farming and agri-environmental stewardship schemes in Devon

A postal survey was undertaken in North Devon looking at entry into England Rural Development Programme (ERDP) environmental schemes in relation to farming system and markets. The main survey was based in and around the North Devon Biosphere reserve. Significantly more farms replied who had Countryside Stewardship (CSS) agreements than from those who were not in the scheme. There was a greater likelihood of small farms joining CSS as were beef, sheep and cereal farms compared with dairy farms. A greater percent of organic farms had CSS agreements compared with the conventional farms. A smaller telephone survey in a CSS target area in South Devon was also undertaken which confirmed these results. Those farms with CSS agreements were more likely to have joined or be joining the new agri-environmental schemes

Classifying pupils by where they live : how welldoes this predict variations in their GCSE results?

Classifying consumers according to the type of neighbourhood in which they live isnow standard practice among most of Britain?s successful consumer facingorganisations. In recent years these ?geodemographic? classifications have becomeincreasingly used in public sector applications. Their use has made it possible notjust to gain a clearer understanding of the level of inequalities that exist betweendifferent types of neighbourhood but also to understand which policy interventionsare likely to be most successful in different localities throughout the country.This paper summarises key findings resulting from the appending of the UK Mosaicneighbourhood classification system to the records of the Pupil Level Annual SchoolCensus. The most significant of these findings is that other than the performance ofthe pupil at an earlier key stage test the type of neighbourhood in which a pupil livesis a more reliable predictor of a pupil?s GCSE performance than any otherinformation held about that pupil on the PLASC database.Analysis then shows the extent to which the performance of pupils from anyparticular type of neighbourhood is also incrementally affected by theneighbourhoods from which the other pupils in the school they attend are drawn. Itfinds that whilst a pupil?s exam performance is affected primarily by the socialbackground of people he or she may encounter at home, the social background offellow school pupils is of only marginally lower significance.These findings suggest that so long as pupils? GCSE performances are so stronglyaffected by the type of neighbourhood in which they live, a school?s league positionbears only indirect relationship to the quality of school management and teaching. Abetter measurement of the latter would be a league table system which took intoaccount the geodemographic profile of each school?s pupil intake.The paper concludes with discussion of the relevance of these findings to thesociology of education, to the debate on consumer choice in public services, to thegeneral appropriateness of adjusting public sector performance metrics to take intoaccount the social mix of service users and to parental strategies in the educationalsector in particular. Classifying consumers according to the type of neighbourhood in which they live isnow standard practice among most of Britain?s successful consumer facingorganisations. In recent years these ?geodemographic? classifications have becomeincreasingly used in public sector applications. Their use has made it possible notjust to gain a clearer understanding of the level of inequalities that exist betweendifferent types of neighbourhood but also to understand which policy interventionsare likely to be most successful in different localities throughout the country.This paper summarises key findings resulting from the appending of the UK Mosaicneighbourhood classification system to the records of the Pupil Level Annual SchoolCensus. The most significant of these findings is that other than the performance ofthe pupil at an earlier key stage test the type of neighbourhood in which a pupil livesis a more reliable predictor of a pupil?s GCSE performance than any otherinformation held about that pupil on the PLASC database.Analysis then shows the extent to which the performance of pupils from anyparticular type of neighbourhood is also incrementally affected by theneighbourhoods from which the other pupils in the school they attend are drawn. Itfinds that whilst a pupil?s exam performance is affected primarily by the socialbackground of people he or she may encounter at home, the social background offellow school pupils is of only marginally lower significance.These findings suggest that so long as pupils? GCSE performances are so stronglyaffected by the type of neighbourhood in which they live, a school?s league positionbears only indirect relationship to the quality of school management and teaching. Abetter measurement of the latter would be a league table system which took intoaccount the geodemographic profile of each school?s pupil intake.The paper concludes with discussion of the relevance of these findings to thesociology of education, to the debate on consumer choice in public services, to thegeneral appropriateness of adjusting public sector performance metrics to take intoaccount the social mix of service users and to parental strategies in the educationalsector in particular

Transients by substructuring with DMAP

Automated substructuring in level 16 of NASTRAN was employed as a preface to the solution of a direct transient analysis. The DMAP ALTER statements written to adapt the substructuring for transient purposes are explained. Data recovery was accomplished with transfer functions. Proof of the success of the method is presented with an application to a missile structure