De Paor, D. 2001. New Interactive Animations for Analysis of Stress, Strain, and Flow. In: Ailleres, L. and Rawling, T. 2001. Animations in Geology. Journal of the Virtual Explorer, 4.
New Interactive Animations for Analysis of Stress, Strain, and Flow

Declan G. De Paor

Revised Version posted - 7 September 2001 and Boston University
P.O. Box 0641, Hull MA 02045, USA
Phone: (781) 925-0264, Fax (781) 925-4248


In geological investigations, stress, strain, and flow in structures are commonly analyzed with the aid of Mohr Diagrams. This paper presents new alternative constructions that build on the techniques familiar to structural geologists from the use of stereonets. The constructions avoid many of the complexities of previous methods, such as off-axis Mohr circles and poles, and present vector data (such as the stress vector acting on an inclined plane) in the correct spatial orientation. The relationship between new and existing constructions is easily demonstrated. The constructions are animated in the electronic version of this paper and may be viewed with a web browser using Macromedia Flash 5.



New Construction

System Requirements

The Underlying Grid

The Simplest Stress Construction: Uniaxial Stress: Animated Version

The Hand-drawn Construction for Uniaxial Stress

Slip on Preexisting Failure Plane

The Construction for Two Stresses of Like Sign

General Failure Envelope

The Construction for Two Stresses of Opposite Sign


The Strain Construction

The Flow Construction