![]() In the attempts to achieve the desired objective, followers of the MLKR have to implicitly return to the representations that have been rejected as early as in Cauchy's works: they do not separate the universal laws of dynamics from the mechanical properties of a particular medium. Besides, the T R object that is reconstructed in the MLKR is not objective: it is not frame indifferent. As a result, MLKR misses the possibility to balance x, i.e., to satisfy the inviolable conservation laws of momentum and angular momentum. In contrast, the "stresses" in MLKR are genetically caused by strains and not related to surface forces. According to the mechanics of deformable solids (MDS), uniform stresses in a quasi-statically deformed macrovolume x are genetically related to the self-equilibrated surface forces acting on x and are completely independent of deformations. In this review, the key ideas of MLKR are discussed and it is shown that the underlying concept of this method is fundamentally fallacious and can lead to results that are arbitrarily inconsistent with reality since under a change in the ignored factors, tensor T R can become almost arbitrary with the same set of slips. This approach ignores the rate of change of the stresses, previous deformation history, and mechanical properties of the block, as well as the ratio of Δt to the stress relaxation time in the block. Tensor T R is determined based on the analysis of N events (N ≥ 4) that occurred in x over the time span Δt using only the data on the slip directions and on the orientation of the slickensided planes. ![]() In the MLKR, the principal axes and the ratio of the differences of the principal values of tensor T (the so-called reduced tensor T R) are reconstructed locally, without taking into account the interaction of x with the contacting blocks, i.e., in such a manner as if macrovolume x were isolated. ![]() In the MLKR, ignoring the equilibrium conditions, the authors assign a studied block (macrovolume x) a certain symmetric tensor T which they call without explanation a stress tensor and which is, in their opinion, the only cause of the observed slips. In the research aimed at determining tectonic stresses from fault-slip data (the seismological data on the focal mechanisms of earthquakes, geological data on slickensides, etc.), in the past few decades, it has become a predominant practice to use the approach that we refer to as the method of the local kinematic reconstruction (MLKR) of stresses and paleostresses. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |