In this contribution, a generalized Cam clay model for cohesive soil materials is introduced. A new formulation not only suppresses evolution of excessive failure stresses and dilatancy rate, but also allows for the reduction of поп-realistic softening behavior of overconsolidated soils predicted when adopting the formulation of classical Cam clay model. More realistic response of the soil is achieved by introducing a new yield function in the dilatation (supercritical or dry) domain, i.e. for OCR > 2. Further, the dependency of the yield function on the Lode angle is adopted and non-associated flow rule is assumed. Finally, the reduction of hardening modulus is shown in comparison to the classical Cam clay model formulation. and Obsahuje seznam literatury
This article describes a theoretical study of non-linear fracture behavior of the Double Cantilever Beam (DCB) configuration. The fracture is analyzed using the J-integral approach. A stress-strain curve with power-law hardening is used for describing the mechanical response of the DCB. It is assumed that the material has the same properties in tension and compression. A model based on Mechanics of materials is applied to find solutions of the J-integral at different levels of the external load. The effect of the exponent of the power law on the non-linear fracture behavior is evaluated. It is found that if higher values of the exponent of the power law are used, the J-integral value increases. The analytical approach developed here is very useful for parametric investigations, since it captures by relatively simple formulae the essential of the non-linear fracture. and Obsahuje seznam literatury