A homogeneous constitutive model for masonry

Masonry has been a broadly used material since the beginning of human life. Despite its popularity, the analysis of masonry structures is a complex ta sk due to the heterogeneity and the non-linear material behaviour. The need for reliable analysis procedures capable of predicting damage evolution an d failure in historical structures in order to design efficient repair and maintenance has motivated the work of many structural analysts in this fiel d. Here the finite element method has emerged as one of the most powerful p rocedures for linear and non-linear analysis of masonry structures. The mai n problem pending is the development of accurate and efficient constitutive models capable of predicting the behaviour of masonry in the non-linear ra nge and this has been the motivation of this work. The constitutive model presented is based on the homogenized anisotropic el astoplasticity previously developed by the authors. The effect of anisotrop y is introduced by means of fictitious isotropic stress and strain spaces. The material properties in the fictitious isotropic spaces are mapped into the actual anisotropic space by means of a consistent fourth-order tensor. The advantage of the model is that the classical theory of plasticity can b e used to model the non-linear behaviour in the isotropic spaces. Details of the model for masonry structures and its implementation in a gen eral non-linear finite element code are given. Examples of application to t he analysis of some masonry structures are presented, showing the efficienc y of the model. Copyright (C) 1999 John Wiley & Sons, Ltd.