In biomedical engineering, earthquake prediction, and underground energy harvesting, it is crucial to indirectly estimate the physical properties of porous media since the direct measurement of those are usually impractical/prohibitive. Here we apply the physics-informed neural networks to solve the inverse problem with regard to the nonlinear Biot's equations. Specifically, we consider batch training and explore the effect of different batch sizes. The results show that training with small batch sizes, i.e., a few examples per batch, provides better approximations (lower percentage error) of the physical parameters than using large batches or the full batch. The increased accuracy of the physical parameters, comes at the cost of longer training time. Specifically, we find the size should not be too small since a very small batch size requires a very long training time without a corresponding improvement in estimation accuracy. We find that a batch size of 8 or 32 is a good compromise, which is also robust to additive noise in the data. The learning rate also plays an important role and should be used as a hyperparameter.
|Title of host publication||Proceedings of 54th ARMA US Rock Mechanics / Geomechanics Symposium|
|Number of pages||10|
|Publisher||American Rock Mechanics Association (ARMA)|
|Article number||ARMA 20–1134|
|Publication status||Published - 2020|
|Event||American Rock Mechanics Association 54th US Rock Mechanics/Geomechanics Symposium - Colorado School of Mines, Golden, United States|
Duration: 28 Jun 2020 → 1 Jul 2020
|Conference||American Rock Mechanics Association 54th US Rock Mechanics/Geomechanics Symposium|
|Location||Colorado School of Mines|
|Period||28/06/2020 → 01/07/2020|
Kadeethum, T., Jørgensen, T. M., & Nick, H. (2020). Physics-informed Neural Networks for Solving Inverse Problems of Nonlinear Biot's Equations: Batch Training. In Proceedings of 54th ARMA US Rock Mechanics / Geomechanics Symposium [ARMA 20–1134] American Rock Mechanics Association (ARMA).