学术报告：CONSTITUTIVE MODELING OF ENGINEERING MATERIALS

CONSTITUTIVEMODELING OF ENGINEERING MATERIALS

9月28日(周一) 下午15:00~16:30

清华大学土木工程系（何善蘅楼）多功能厅

Xavier Martínez García

Vicedean Director of studiesat Facultat de Nàutica de Barcelona(FNB)

Professor at UniversitatPolitècnica de Catalunya (UPC)

Researcher at CIMNE

webpage:https://web.cimne.upc.edu/users/xmartinez/

Current presentationstarts with a brief introduction about the Polytechnic University of Catalonia (UPC) and the International Center for Numerical Methods in Engineering (CIMNE),and a description of some of the research lines of this last one.

Afterwards it ispresented the CIMNE Composites – PLCd Group, and some of the research topics in which we have worked or we are still working. Of those, the presentation will focus on some of the numerical models that the group has developed for the simulation of engineering materials.

PLCd group has been working in the development of constitutive models to characterize the non-linear response of composite materials since 1989. Among the different models proposed, we can remark a damage model for concrete with a different response for traction and compression stresses, a general procedure to account for large material anisotropy, or the models that will be presented hereafter.

The first model that will be presented is a comprehensive formulation to predict fatigue failure inmetallic materials. The formulation uses a damage constitutive approach in case of high cycle fatigue and a plasticity approach in case of low and ultra low cycle fatigue.

The next two formulations are not constitutive models, but procedures to simulate composite materials taking into account the non-linear response of their constituents.

The first one, the serial/parallel mixing theory, can be understood as a phenomenological homogenization, in which the mechanical response of the composite is obtained from the constitutive models of its constituents. This theory allows anaccurate prediction of the non-linear response and failure of composite laminates (reinforced concrete can be analyzed as a laminate).

The second onecorresponds to a numerical homogenization procedure, in which the material is characterized with a finite element model of its micro-structure. The extraordinary cost that represents analyzing a real structure with anhomogenized model is reduced thanks to an efficient strategy developed by thegroup.