Search results for " Cost"

Analysis of composite laminates with imperfect bonding conditions

2007

A multidomain boundary integral formulation for the analysis of composite laminates with imperfect interlaminar interfaces is presented. An imperfect interface refers to a zero-thickness interfacial layer across which displacement discontinuity may occur while interlaminar tractions must remain continuous. The displacement discontinuity is considered through a spring model in order to model the adhesive layer among two adjacent laminae. No auxiliary elements are needed to implement the imperfect interface since the spring coefficients, characterizing the different bonding interface conditions, are taken into account inside the assembled influence matrices. To assess the reliability and the …

A model for low-cycle fatigue in micro-structured materials

2020

A microscale formulation for low-cycle fatigue degradation in heterogeneous materials is presented. The interface traction-separation law is modelled by a cohesive zone model for low-cycle fatigue analysis, which is developed in a consistent thermodynamic framework of elastic-plastic-damage mechanics with internal variables. A specific fatigue activation condition allows to model the material degradation related to the elastic-plastic cyclic loading conditions, with tractions levels lower than the static failure condition. A moving endurance surface, in the classic framework of kinematic hardening, enables a pure elastic behaviour without any fatigue degradation for low levels of cyclic tra…

3D boundary element analysis of delamination crack using the Modified Crack Closure Integral

2012

Coupled VEM–BEM Approach for Isotropic Damage Modelling in Composite Materials

2023

Numerical prediction of composite damage behaviour at the microscopic level is still a challenging engineering issue for the analysis and design of modern materials. In this work, we document the application of a recently developed numerical technique based on the coupling between the virtual element method (VEM) and the boundary element method (BEM) within the framework of continuum damage mechanics (CDM) to model the in-plane damage evolution characteristics of composite materials. BEM is a widely adopted and efficient numerical technique that reduces the problem dimensionality due to its underlying formulation. It substantially simplifies the pre-processing stage and decreases the compu…

Fast Hierarchical Boundary Element Method for Large Scale 3-D Elastic Problems

2010

This chapter reviews recent developments in the strategies for the fast solution of boundary element systems of equations for large scale 3D elastic problems. Both isotropic and anisotropic materials as well as cracked and uncracked solids are considered. The focus is on the combined use the hierarchical representation of the boundary element collocation matrix and iterative solution procedures. The hierarchical representation of the collocation matrix is built starting from the generation of the cluster and block trees that take into account the nature of the considered problem, i.e. the possible presence of a crack. Low rank blocks are generated through adaptive cross approximation (ACA) …

Structural Health Monitoring of delaminated composite structures by the Boundary Element method

2012

Structural Health Monitoring (SHM) for composite materials is becoming a primary task due to their extended use in safety critical applications. Different methods, based on the use of piezoelectric transducers, strain memory alloys as well as of fibre optics, has been successfully proposed to detect and monitor damage in composite structural components with particular attention focused on delamination cracks. In the present paper a Structural Health Monitoring model based on the use of piezoelectric sensors, already proposed by the authors for isotropic damaged components, is extended to delaminated composite structures. The dynamic behavior of the host damaged structure and the bonded piez…

A HYBRID VEM/BEM NUMERICAL TECHNIQUE FOR SIMULATING DAMAGE IN COMPOSITE MATERIALS

2021

Composite materials are nowadays widely used in the aerospace sector both for primary and secondary structures for their high mechanical properties and the ability to model them according to project needs. Therefore, accurately predicting material behaviour when subjected to operating loads is extremely important in making the design process more efficient. For this purpose, computational approaches based on continuum damage mechanics have been largely used to study the progressive loss of material integrity due to the propagation and coalescence of microscopic defects. In this contribution, a recently developed hybrid computational technique, which combines the Virtual Element Method (VEM)…

Application of dual boundary element method in active sensing

2013

In this paper, a boundary element method (BEM) for the dynamic analysis of 3D solid structures with bonded piezoelectric transducers is presented. The host structure is modelled with BEM and the piezoelectric transducers are formulated using a 3D semi-analytical finite element approach. The elastodynamic analysis of the entire structure is carried out in Laplace domain and the response in time domain is obtained by inverse Laplace transform. The BEM is validated against established finite element method (FEM).

Tsunami Vulnerability Evaluation for a Small Ancient Village on Eastern Sicily Coast

2022

The Ionian sea is prone to tsunamis due to its proximity to the Calabrian subduction zone, which is one of the major tsunamigenic areas of the Mediterranean. The tsunami disaster risk is, nowadays, significantly higher due to the increased exposure of buildings as a result of the economic and touristic growth of the Mediterranean coastal areas. This study focuses on Marzamemi, a small village in the western coast of Sicily, since its morphology and human presence amplify the need to assess its buildings’ vulnerability. The main objective of this research is to quantify the building vulnerability to tsunami hazards using a physical and realistic tsunami scenario. For this purpose, the relati…

A new shoreline boundary condition for a highly nonlinear 1DH Boussinesq model for breaking waves

2008

In order to model the wave motion and, in turn, the flow, within the nearshore region, in the last decades the derivation and the application of Boussinesq type of models have been extensively investigated. Nevertheless, in the framework of such depth integrated numerical models, the problems of modeling wave breaking and moving onshore boundary at the shoreline are not trivial and several approaches have been proposed to overcome these limits. In the present work an effort toward a more physical based model of the surf and the swash zone has been accomplished. In particular, starting from the work of Musumeci et al. (2005), a new model of the shoreline boundary condition has been implement…