Structures in Other Domains The methodology of structural analysis discussed in this article has been applied beyond the narrow realm of natural language syntax that we have discussed in this article. Within the study of language, similar methods of analysis have been pervasively applied to the study of sounds (phonology), words (morphology), and meanings (semantics), yielding a range of of abstract structural representations whose properties bear considerable explanatory burden. There are a wealth of cases in each of these domains analogous to those discussed here, though space prevents us from going in these (see Akmajian, Demers, Farmer and Harnish 1995 for a traditional overview, and Jackendo 1994 for one more focused on connections with cognitive science). Additionally, these representations have shed substantial light on the processes of language acquisition and language change. It has been found that variation in the types of sentences that are used, whether during the course of children's acquisition of their native languages or in the centuries-long periods of linguistic change, are best characterized not as super cial and haphazard alterations, but rather in terms of parametric modi cations to the fundamental underlying grammatical rules and constraints. Moving outside the domain of language, one application of these same methods has been in the study of music cognition. Just as the representations of linguistic theory arise out of an attempt to model speakers' intuitions about well-formedness and possible meanings of the sentences of their

Structural analysis

Numerical analysis of 3D dry-stone masonry structures by combined finite-discrete element method

The realities of additively manufactured concrete structures in practice

Comparison of in-plane and out-of-plane failure modes of masonry arch bridges using discontinuum analysis

http://repositorium.sdum.uminho.pt/bitstream/1822/68377/1/ManuscriptStructures.pdf

Simulation of the in-plane structural behavior of unreinforced masonry walls and buildings using DEM

The failure mechanism and maximum collapse load of masonry structures may change significantly under static and dynamic excitations depending on their internal arrangement and material properties. Hence, it is important to understand correctly the nonlinear behavior of masonry structures in
order to adequately assess their safety and propose efficient strengthening measures, especially for historical constructions. The discrete element method (DEM) can play an important role in these studies. This paper discusses possible collapse mechanisms and provides a set of parametric analyses by considering the influence of material properties and cross section morphologies on the out of plane strength of masonry
walls. Detailed modeling of masonry structures may affect their mechanical strength and displacement capacity. In particular, the structural behavior of stacked and rubble masonry walls, portal frames, simple combinations of masonry piers and arches, and a real structure is discussed using DEM. It is further
demonstrated that this structural analysis tool allows obtaining excellent results in the description of the nonlinear behavior of masonry structures.

/pdf/discrete-element-modeling-of-masonry-structures-validation-2fe7c39dtm.pdf

Discrete element modeling of masonry structures: Validation and application

This study proposes new contact models to be incorporated into discrete element method (DEM) to more accurately simulate the tensile softening in quasi-brittle materials, such as plain concrete and masonry with emphasis on fracture mechanism and post-peak response. For this purpose, a plain concrete specimen (double notched) and stack bonded masonry prism under direct tensile test are modeled. Furthermore, mixed mode crack propagation is investigated in concrete and brickwork assemblages. Two modeling approaches are proposed, the simplified and detailed meso modeling, both based on DEM. In the simplified meso-model, a smooth contact surface is considered between two separate blocks, whereas the internal structure of the material is explicitly represented as a tessellation into random polyhedral blocks in the detailed meso-model. Furthermore, recently developed tensile softening contact constitutive models implemented into a commercial discrete element code (3DEC) are used to simulate the softening behavior of concrete and masonry. As an important novel contribution, it is indicated that the proposed computational models successfully capture the complete (pre- and post-peak) material behavior and realistically replicate the cracking mechanism. Additionally, a sensitivity analysis demonstrates the influence of the various micro-contact parameters on the overall response of the examined materials.

/pdf/simulation-of-uniaxial-tensile-behavior-of-quasi-brittle-56cmbsqhn6.pdf

Simulation of uniaxial tensile behavior of quasi-brittle materials using softening contact models in DEM

This study proposes an alternative approach to modeling the failure mechanisms of brickwork assemblages under combined shear–compression, shear–tension (parallel to bed joints), and compression–flexural loadings using the discrete element method (DEM). In this context, recently developed elastic-softening contact constitutive laws considering the mode-I and mode-II fracture energies are implemented into the dynamic solution scheme of the DEM to simulate the mechanical interaction between mortar and masonry units represented via 3D polyhedral blocks. Different experimental studies from the literature are used to validate the proposed computational models, and good agreement is found in terms of strength, material behavior, and fracture mechanisms. The findings of this research indicate that the proposed modeling strategy is successful in predicting the macro behavior of masonry under various complex fracture modes based on the defined micro properties. Sensitivity analyses are also performed by varying the fracture energy and valuable inferences are made with respect to the stress–displacement response and failure mechanisms of masonry.

Bora Pulatsu

Papers

Discrete element modeling of masonry structures: Validation and application

Comparison of in-plane and out-of-plane failure modes of masonry arch bridges using discontinuum analysis

Simulation of the in-plane structural behavior of unreinforced masonry walls and buildings using DEM

Simulation of uniaxial tensile behavior of quasi-brittle materials using softening contact models in DEM

Discontinuum analysis of the fracture mechanism in masonry prisms and wallettes via discrete element method