The NAFEMS Benchmark Challenge - 05
Dynamic Characteristics of a Truss Structure
April 12th 2016
The Benchmark Challenge was launched the October 2014 edition of Benchmark and on the NAFEMS Challenge blog. The concept behind this initiative is to provide seemingly simply problems for readers to consider. The challenges will typically contain in interesting ‘twist’ which is intended to be thought-provoking and to provide an opportunity for learning.
The publication of this solution represents a complete year of the Challenge and provides a good opportunity to reflect on the initiative. During this period, the following four BenchmarkChallenges were presented, together with their solutions:
- NBC01: Stress at the Centre of a Square Plate with Linear Boundary Tractions
- NBC02: Assessment of a Simply Supported Plate with Uniformly Distributed Load
- NBC03: Understanding and Explaining theNature of the Plane Strain Approximation
- NBC04: Poisson’s Ratio for a Steel Plate
These challenges and their solutions will be published in a NAFEMS book entitled ‘The NAFEMS Benchmark Challenge 2015/16’, in the coming months. The book will include the original challenges and solutions, as well additional details not presented in the original responses. It is hoped that members will find this to be a useful educational and training resource.
There were many excellent responses submitted by NAFEMS members. In particular, Jack Reijmers, a Specialist Engineer at Nevesbu in The Netherlands, submitted four excellent solutions and has therefore been selected as the winner of this year's challenge prize of an iPad mini.
An unexpected by-product of the challenge has been the development of a collaborative research project between the editor (Angus Ramsay of Ramsay Maunder Associates) and three of the respondents with a common interest in achieving accurate elastic and plastic solutions for plate problems. This work was prompted by the findings made in NBC02, where published solutions were found to be rather inaccurate when compared to the sort of results that can be generated using modern finite element tools. A series of five articles are planned covering the design/assessment of plate members, and it is hoped that these might be published by one of the engineering institutions in the UK. Publishers McGraw-Hill, have also asked the editors to update the data in Roark’s ‘Formulas for Stress & Strain’ for the next edition, and these articles will form a useful source of peer-reviewed reference for this task.
The success of the Benchmark Challenge initiative, as judged by interest from readers of the magazine and others further afield, means that it will be continued for a further year. The fifth challenge involves the ‘Dynamic Characteristics of a Truss Structure’ and is published above. As usual, readers are encouraged to take part and to submit their responses to NAFEMS for an appraisal, and if successful, receive a certificate and NAFEMS business card holder.