In general, changing property is placed on Y-axis and independent property is kept on X-axis. But in this case it is in reverse as changing quantity is strain still is placed on X-axis.
Is there any particular reason/logic behind this?
more than changing property, in a X-Y plot generally the independent variable is taken in X-axis and the dependent one is taken in Y-axis. In stress-strain curve as strain or the deformation is independent and comes as result of the externally applied force, so it is taken in X-axis. Where as Stress comes in order to resist the deformation in terms of Resisting force. so it is dependent on strain and comes in Y-axis. so there nothing reverse here and is completely satisfying.
EXTERNAL FORCE---.> DEFORMATION---> STRAIN---> RESISTING FORCE----> STRESS.
(Hence strain comes first and independent and in x-axis, where as stress comes later and dependent on strain and in Y-axis)
more than changing property, in a X-Y plot generally the independent variable is taken in X-axis and the dependent one is taken in Y-axis. In stress-strain curve as strain or the deformation is independent and comes as result of the externally applied force, so it is taken in X-axis. Where as Stress comes in order to resist the deformation in terms of Resisting force. so it is dependent on strain and comes in Y-axis. so there nothing reverse here and is completely satisfying.
EXTERNAL FORCE---.> DEFORMATION---> STRAIN---> RESISTING FORCE----> STRESS.
(Hence strain comes first and independent and in x-axis, where as stress comes later and dependent on strain and in Y-axis)
Hooks law also says that stress is proportional to strain. It is then obvious that stress should be plotted on y axis and strain on x axis.The explanation why stress should depend on strain has already been given by Dr. Dasmohapatra.
It is both a case of mathematical dependence (as explained by Shashikanta Dasmohapatra and Dr Dr A. Kumar) and a case of tradition.
If a load is applied, a deformable body deforms. So the deformation depend on the load. However, it is customary to plot force in vertical axis and deformation in the horizontal axis.
It is a bit bizarre but I think the test equipment usually applies a fixed strain and measures the stress needed, rather than the other way round, so the usual way of plotting it reflects the measurement. It's been years since I did mechanical testing though so I'm happy to be corrected.
Stress is the non-observable cause for the observable effect strain. Therefore, one may ask why stress is put on Y-axis & strain is put on X-axis. The reason seems to be that tension tests are typically made displacement controled (X-axis) and stress is measured as dependent variable (Y-axis).
This is not contradicting my first statement. In fact the load cell measures (observes) deformation which is converted to load by Hooke's law (load itself is non-observable).
Generally, for plotting any graph 'Cause' is always plotted on X-axis while 'effect' is plotted on Y-axis. In tensile test, strain is the cause and this strain causes effect in terms of stress as explained in above answers.
People generally like to graph the situation where every value on the x-axis has a unique solution on the y-axis. Consider looking at a graph of sin(x) vs arcsin(x). If the material is purely elastic or an ideal plastic whether you show a stress-strain vs strain-stress graph does not really matter. However if the material shows dynamic recovery or exhibits stick-slip etc. a strain-stress graph would look very strange.
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