Stability of No-Tension Masonry Walls having a Non-Linear Constitutive Law

2009 ◽  
Author(s):  
I. Mura
Keyword(s):  
Constitutive Law ◽  
Masonry Walls ◽  
Non Linear

Reducing Seismic out of Plane Vulnerability of Masonry Church Façades through Optimization of Capacity Spectrum by Tie Rods

2019 ◽  
Vol 817 ◽  
pp. 325-333
Author(s):  
Simonetta Baraccani ◽  
Giorgio Dan ◽  
Angelo Di Tommaso ◽  
Tomaso Trombetti
Keyword(s):  
Masonry Walls ◽  
Collapse Mechanisms ◽  
Capacity Spectrum ◽  
Construction Techniques ◽  
Non Linear ◽  
Out Of Plane ◽  
Recent Earthquakes ◽  
Discrete Element Methods ◽  
Tie Rods ◽  
The Church

The analyses of the structural damages detected on the Italian churches after the recent earthquakes (Emilia 2012, Umbria-Marche 2016) highlighted the high vulnerability to the overturning of the façades. The façades collapse mechanisms are strongly dependent on the connection details between orthogonal masonry walls, the windows, the construction techniques and the possible restraining horizontal elements, such as tie-beams, bi-lateral connected roof, etc. Several studies focus on the evaluation of vulnerability of the church façades using different approaches, from global analyses (FEM and /or Discrete Element Methods) of the entire building, to local analyses (linear and non-linear kinematic approaches). The aims of the present paper is to use the method based on capacity spectra to evaluate the vulnerability of the church facades and the optimization of specific devices as tie-rods to improve their seismic behavior. The non-linear approach is now accepted by several standards regarding the evaluation of risks of collapse mechanisms for masonry walls of the facades. Appropriate devices have been considered in order to calibrate the capacity curve and to optimize the interventions. The out of plane rotation of blocks can be modified with various elasto-perfect-plastic tendons with appropriate retentions (while composite materials could be used to preserve integrity of blocks). The tendons can be allocated in proper location and the length of each calibrated to best determine their stiffness. This procedure have been here applied to the study of the façade of Aula Magna S. Lucia of the Bologna University, considering also the problem of the interaction with the structure of the roof.

Non-linear continuous model for three leaf masonry walls

2020 ◽  
Vol 244 ◽  
pp. 118356 ◽  
Author(s):  
Claudia Brito de Carvalho Bello ◽  
Giosuè Boscato ◽  
Emilio Meroi ◽  
Antonella Cecchi
Keyword(s):  
Continuous Model ◽  
Masonry Walls ◽  
Non Linear

Numerical analysis of the dynamic interaction between a non-pneumatic mechanical elastic wheel and soil containing an obstacle

2016 ◽  
Vol 231 (6) ◽  
pp. 731-742 ◽  
Author(s):  
Xianbin Du ◽  
Youqun Zhao ◽  
Qiang Wang ◽  
Hongxun Fu
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Interaction Model ◽  
Dynamic Interaction ◽  
Constitutive Law ◽  
Elastic Wheel ◽  
Non Linear ◽  
Dimensional Finite Element ◽  
Mechanical Elastic Wheel ◽  
Three Dimensional Finite Element

An innovative non-pneumatic tyre called the mechanical elastic wheel is introduced; significant challenges exist in the prediction of the dynamic interaction between this mechanical elastic wheel and soil containing an obstacle owing to its highly non-linear properties. To explore the mechanical properties of the mechanical elastic wheel and the soil, the finite element method is used, and a non-linear three-dimensional finite element wheel–soil interaction model is also established. Hyperelastic incompressible rubber, which is one of the main materials of the mechanical elastic wheel, is analysed using the Mooney–Rivlin model. The modified Drucker–Prager cap plasticity constitutive law is utilized to describe the behaviour of the soil, and the obstacle is represented as an elastic body. Simulations with different rotational speeds of the mechanical elastic wheel were conducted. The stress distribution and the displacement of the mechanical elastic wheel and the soil were obtained, and the effects of different rotational speeds on the displacement, the velocity and the acceleration of the hub centre are presented and discussed in detail. These results can provide useful information for optimization of the mechanical elastic wheel.

scholarly journals In-Plane Behaviour of Masonry Walls: Numerical Analysis and Design Formulations

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5780
Author(s):  
Thomas Celano ◽  
Luca Umberto Argiento ◽  
Francesca Ceroni ◽  
Claudia Casapulla
Keyword(s):  
Failure Modes ◽  
Shear Failure ◽  
Numerical Models ◽  
Experimental Tests ◽  
Element Model ◽  
Masonry Walls ◽  
Analysis And Design ◽  
Non Linear ◽  
Failure Loads ◽  
Modelling Approaches

This paper presents the results of several numerical analyses aimed at investigating the in-plane resistance of masonry walls by means of two modelling approaches: a finite element model (FEM) and a discrete macro-element model (DMEM). Non-linear analyses are developed, in both cases, by changing the mechanical properties of masonry (compressive and tensile strengths, fracture energy in compression and tension, shear strength) and the value of the vertical compression stress applied on the walls. The reliability of both numerical models is firstly checked by means of comparisons with experimental tests available in the literature. The analyses show that the numerical results provided by the two modelling approaches are in good agreement, in terms of both failure loads and modes, while some differences are observed in their load-displacement curves, especially in the non-linear field. Finally, the numerical in-plane resistances are compared with the theoretical formulations provided by the Italian building code for both flexural and shear failure modes and an amendment for the shape factor ‘b’ introduced in the code formulation for squat walls is proposed.

scholarly journals Application of the Generalized Nonlinear Constitutive Law to Hollow-Core Slabs

2021 ◽  
Author(s):  
Natalia Staszak ◽  
Tomasz Garbowski ◽  
Barbara Ksit
Keyword(s):  
Finite Element ◽  
Cross Section ◽  
Crack Opening ◽  
Constitutive Law ◽  
Fe Model ◽  
Hollow Core ◽  
Linear Finite Element ◽  
Deformation State ◽  
Non Linear ◽  
Nonlinear Constitutive Law

The non-linear analysis of hollow-core concrete slabs requires the use of advanced numerical techniques, proper constitutive models both for concrete and steel as well as particular computational skills. If prestressing, cracking, crack opening, material softening, etc. are also to be taken into account, then the computational task can far exceed the capabilities of an ordinary engineer. In order for the calculations to be carried out in a traditional design office, simplified calculation methods are needed. Preferably based on the linear finite element (FE) method with a simple approach that takes into account material nonlinearities. In this paper the simplified analysis of hollow-core slabs based on the generalized nonlinear constitutive law is presented. In the proposed method a simple decomposition of the traditional iterative linear finite element analysis and the non-linear algebraic analysis of the plate cross-section is used. Through independent analysis of the plate cross-section in different deformation states, a degraded plate stiffness can be obtained, which allows iterative update of displacements and rotations in the nodes of the FE model. Which in turn allows to update the deformation state and then correct translations and rotations in the nodes again. The results obtained from the full detailed 3D nonlinear FEM model and from the proposed approach are compared for different slab cross-sections. The obtained results from both models are consistent.

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