Justifiable Precision and Accuracy in Structural Engineering Calculations: In Search of a Little Less Precision and Supposed Accuracy

Abstract

As a result of technological progression, mathematical calculations may currently be carried out to levels of precision which are orders of magnitude greater than were possible only decades ago. Consequently, design professionals are producing structural engineering calculations to unrealistically high levels of precision. Many engineers advocate the reporting of structural design calculations to four, five, and even six significant figures, with disregard to the implicit precision on which modern design codes and specifications are based. In response to these expectations, historical documents pertaining to structural design have been reviewed, methods of structural analysis have been considered, and practical design situations have been reviewed in order to remind the structural engineer of the inherent limitations of the precision of structural engineering calculations. Conclusions have been drawn from these considerations, and a recommendation with respect to an appropriate level of precision in structural design is presented.