PMC

The results for the (a) wood pole and (b) sapling tests. Here, we used the function with negative sign, -1/E* cos(D-θg), because this form is adapted to outputs of a strain gauge which gives a positive value for tension and a negative value for compression. For each panel, circles show the measurement values from each rotation and lines show the fitted curves. D (degrees) is the radial direction of loading F, θ_g (degrees) is the direction of each strain gauge on the specimen, and E (GPa) is the modulus of elasticity. Black open circles and black dashed lines, strain gauge td1; black solid circles and black solid lines, strain gauge bd1; grey open circles and grey dashed lines, strain gauge td2; and grey solid circles and grey solid lines, strain gauge bd2. For the E and θ_g values of each strain gauge, see .

Pole figures (PFs) at various deformation positions at 760 °C: (a) at the grip position, (b) the gauge section near the grip, (c) the middle of the gauge section, and (d) section near the tip of the fracture.

Fabrication process of the device. (a) Lift-off process for the making of the strain gauges on polyimide film and (b) the assembly process of the base, pole, and strain gauge.

Details on the 3-grain cluster (a) 3D visualization of the grains (b); XZ slice through the 3 grains; (c) inverse pole figure of the gauge length with the 3 grain orientations of interest highlighted; (d) integration range automatically determined at each loading step.