Homogenised Dynamic Material Model for Brick Masonry and Its Application

2010 ◽  
Vol 168-170 ◽  
pp. 528-531
Author(s):  
Xin Zhong Li ◽  
Xue Ying Wei ◽  
Jun Hai Zhao
Keyword(s):  
Computational Cost ◽  
Dynamic Test ◽  
Material Model ◽  
Masonry Wall ◽  
Brick Masonry ◽  
Building Structures ◽  
Dynamic Material Model ◽  
Blast Response ◽  
Partition Walls ◽  
Brick And Mortar

Brick masonry is a traditional building material widely used loading-bearing or partition walls in various building structures. The detailed distinctive modelling of brick and mortar of a realistic masonry structure or a structure with masonry infilled walls are usually not possible due to the computational cost. In this paper, a homogenized dynamic material model which including the damage of brick and mortar and strain rate effect is developed based on dynamic test results of brick and mortar. The proposed homogenized material model was used in analysis of blast response of brick masonry wall.

scholarly journals Experimental and Numerical Study of Behaviour of Reinforced Masonry Walls with NSM CFRP Strips Subjected to Combined Loads

Buildings ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 103
Author(s):  
Houria Hernoune ◽  
Benchaa Benabed ◽  
Antonios Kanellopoulos ◽  
Alaa Hussein Al-Zuhairi ◽  
Abdelhamid Guettala
Keyword(s):  
Failure Modes ◽  
Numerical Study ◽  
Masonry Wall ◽  
Brick Masonry ◽  
Masonry Walls ◽  
Near Surface ◽  
Combined Loads ◽  
Reinforced Masonry ◽  
Brick And Mortar ◽  
Near Surface Mounted

Near surface mounted (NSM) carbon fibers reinforced polymer (CFRP) reinforcement is one of the techniques for reinforcing masonry structures and is considered to provide significant advantages. This paper is composed of two parts. The first part presents the experimental study of brick masonry walls reinforced with NSM CFRP strips under combined shear-compression loads. Masonry walls have been tested under vertical compression, with different bed joint orientations 90° and 45° relative to the loading direction. Different reinforcement orientations were used including vertical, horizontal, and a combination of both sides of the wall. The second part of this paper comprises a numerical analysis of unreinforced brick masonry (URM) walls using the detailed micro-modelling approach (DMM) by means of ABAQUS software. In this analysis, the non-linearity behavior of brick and mortar was simulated using the concrete damaged plasticity (CDP) constitutive laws. The results proved that the application of the NSM-CFRP strips on the masonry wall influences significantly strength, ductility, and post-peak behavior, as well as changing the failure modes. The adopted DMM model provides a good interface to predict the post peak behavior and failure mode of unreinforced brick masonry walls.

Numerical Derivation of Pressure-Impulse Diagrams for Unreinforced Brick Masonry Walls

2011 ◽  
Vol 368-373 ◽  
pp. 1435-1439
Author(s):  
Xue Ying Wei ◽  
Tuo Huang ◽  
Nan Li
Keyword(s):  
Blast Loading ◽  
Material Model ◽  
Unreinforced Masonry ◽  
Masonry Walls ◽  
Strain Rate Effects ◽  
Pressure Impulse ◽  
Damage Level ◽  
Blast Response ◽  
Rate Effects ◽  
Brick And Mortar

Pressure-impulse diagrams have been extensively used for damage assessments of structural components subject to a specified blast loading. In this paper, a numerical method is used to generate pressure-impulse diagrams for unreinforced masonry walls subjected to blast loading. A previously developed plastic damage material model accounting for strain rate effects is used for brick and mortar. Three levels of damage criteria are defined based on maximum deflection of the wall and rotation of the supports. The obtained blast response for unreinforced masonry walls are validated against field test data. It is shown that the obtained pressure-impulse diagrams have an improved ability to evaluate the damage level of masonry walls.

Influence of Sulphate on the Moisture Movement of Calcium Silicate Brick Masonry Wall

2010 ◽  
Vol 133-134 ◽  
pp. 201-204
Author(s):  
Ibrahim Mohamad H. Wan ◽  
B.H. Abu Bakar ◽  
M.A. Megat Johari ◽  
P.J. Ramadhansyah
Keyword(s):  
Relative Humidity ◽  
Calcium Silicate ◽  
Masonry Wall ◽  
Sodium Sulphate ◽  
Brick Masonry ◽  
Masonry Walls ◽  
Moisture Movement ◽  
Moisture Expansion ◽  
Curing Period ◽  
Wet Condition

This paper presents the behaviour of moisture movement of calcium silicate brick masonry walls exposed to sodium sulphate environment. The walls were exposed to three sodium sulphate conditions with sulphate concentrations of5%, 10% and 15%. For comparison, some walls were also exposed to dry and wet condition which acts as a control conditions. All specimens were prepared and cured under polythene sheet for 14 days in a controlled environmental room and maintained at relative humidity and temperature of 80 ± 5% and 25 ± 2°C, respectively. After the curing period, the specimens were exposed to sodium sulphate as well as drying and water exposures, during which moisture movement was measured and monitored for a period of up to 7 months. As a result, the moisture expansion was observed and recorded for all masonry wall specimens after exposed to the sulphate condition.

scholarly journals Research on Damage Characteristics of Brick Masonry under Explosion Load

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Jifeng Wei ◽  
Zhixin Du ◽  
Yonghui Zheng ◽  
Oundavong Ounhueane
Keyword(s):  
Power Function ◽  
Explosive Charge ◽  
Masonry Wall ◽  
Pressure Vessels ◽  
Brick Masonry ◽  
Ejection Velocity ◽  
Load Bearing ◽  
Damage Characteristics ◽  
Explosion Load ◽  
The Relationship

As the main structural component of partition wall or load-bearing wall, brick masonry has been widely used in construction engineering. However, brick and mortar are all brittle materials prone to crack. Nowadays, fireworks, gas stoves, high-pressure vessels, and other military explosives may explode to damage nearby structures. Many explosion casualties had shown that the load-bearing capacity of brick masonry decreased dramatically and cracks or fragments appeared. Previous studies mainly focused on noncontact explosion in which shock wave is the main damage element. In fact, the response and damage effect of brick masonry wall under contact explosion are more complex, which attracts more attention now. In order to explore the damage characteristics of brick masonry under explosion load, a series of simulations and verification experiments are conducted. RHT and MO granular material models are introduced to describe the behaviour of brick and masonry, respectively, in simulation. The combination effect of front compressive wave and back tensile wave are main factors influencing the breakage of masonry wall. The experimental results are well in accordance with the simulation results. The front cross section dimension of crater is closely related to the radius of spherical explosive charge. A power function predictive model is developed to express the relationship between the radius of hole and the radius of explosive. Furthermore, with increasing the quantity of explosive charge, the number and ejection velocity of fragments are all increased. The relationship between maximum ejection velocity and the quantity of explosive also can be expressed as a power function model.

scholarly journals Identification of Fractional Damping Parameters in Structural Dynamics Using Polynomial Chaos Expansion

2021 ◽  
Vol 2 (4) ◽  
pp. 956-975
Author(s):  
Marcel S. Prem ◽  
Michael Klanner ◽  
Katrin Ellermann
Keyword(s):  
Polynomial Chaos ◽  
Constitutive Relations ◽  
Computational Cost ◽  
Material Model ◽  
Polynomial Chaos Expansion ◽  
Computational Technique ◽  
Chaos Expansion ◽  
Material Damping ◽  
Fractional Damping ◽  
Assembly Technique

In order to analyze the dynamics of a structural problem accurately, a precise model of the structure, including an appropriate material description, is required. An important step within the modeling process is the correct determination of the model input parameters, e.g., loading conditions or material parameters. An accurate description of the damping characteristics is a complicated task, since many different effects have to be considered. An efficient approach to model the material damping is the introduction of fractional derivatives in the constitutive relations of the material, since only a small number of parameters is required to represent the real damping behavior. In this paper, a novel method to determine the damping parameters of viscoelastic materials described by the so-called fractional Zener material model is proposed. The damping parameters are estimated by matching the Frequency Response Functions (FRF) of a virtual model, describing a beam-like structure, with experimental vibration data. Since this process is generally time-consuming, a surrogate modeling technique, named Polynomial Chaos Expansion (PCE), is combined with a semi-analytical computational technique, called the Numerical Assembly Technique (NAT), to reduce the computational cost. The presented approach is applied to an artificial material with well defined parameters to show the accuracy and efficiency of the method. Additionally, vibration measurements are used to estimate the damping parameters of an aluminium rotor with low material damping, which can also be described by the fractional damping model.

Experimental study on seismic performance of fire-exposed perforated brick masonry wall

2018 ◽  
Vol 180 ◽  
pp. 77-91 ◽  
Author(s):  
Jin Zhang ◽  
Hao Ma ◽  
Cheng Li ◽  
Qingfeng Xu ◽  
Weibin Li
Keyword(s):  
Experimental Study ◽  
Seismic Performance ◽  
Masonry Wall ◽  
Brick Masonry

scholarly journals Hot Deformation Treatment of Grain-Modified Mg–Li Alloy

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4557
Author(s):  
Mariusz Król ◽  
Przemysław Snopiński ◽  
Marek Pagáč ◽  
Jiří Hajnyš ◽  
Jana Petrů
Keyword(s):  
Hot Deformation ◽  
Cast Alloy ◽  
Material Model ◽  
Strain Rate Range ◽  
Al Alloy ◽  
Grain Refiner ◽  
Systematic Analysis ◽  
Dynamic Material Model ◽  
Instability Map

In this work, a systematic analysis of the hot deformation mechanism and a microstructure characterization of an as-cast single α-phase Mg–4.5 Li–1.5 Al alloy modified with 0.2% TiB addition, as a grain refiner, is presented. The optimized constitutive model and hot working terms of the Mg–Li alloy were also determined. The hot compression procedure of the Mg–4.5 Li–1.5 Al + 0.2 TiB alloy was performed using a DIL 805 A/D dilatometer at deformation temperatures from 250 °C to 400 °C and with strain rates of 0.01–1 s−1. The processing map adapted from a dynamic material model (DMM) of the as-cast alloy was developed through the superposition of the established instability map and power dissipation map. By considering the processing maps and microstructure characteristics, the processing window for the Mg–Li alloy were determined to be at the deformation temperature of 590 K–670 K and with a strain rate range of 0.01–0.02 s−1.

scholarly journals Hot Deformation Behavior of a New Al–Mn–Sc Alloy

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 22
Author(s):  
Weiqi Kang ◽  
Yi Yang ◽  
Sheng Cao ◽  
Lei Li ◽  
Shewei Xin ◽  
...  
Keyword(s):  
Flow Stress ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Material Model ◽  
Strain Rates ◽  
Hot Workability ◽  
Hot Deformation Behavior ◽  
Hollomon Parameter ◽  
Dynamic Material Model ◽  
Optimal Processing

The hot deformation behavior of a new Al–Mn–Sc alloy was investigated by hot compression conducted at temperatures from 330 to 490 °C and strain rates from 0.01 to 10 s−1. The hot deformation behavior and microstructure of the alloy were significantly affected by the deformation temperatures and strain rates. The peak flow stress decreased with increasing deformation temperatures and decreasing strain rates. According to the hot deformation behavior, the constitutive equation was established to describe the steady flow stress, and a hot processing map at 0.4 strain was obtained based on the dynamic material model and the Prasad instability standard, which can be used to evaluate the hot workability of the alloy. The developed hot processing diagram showed that the instability was more likely to occur in the higher Zener–Hollomon parameter region, and the optimal processing range was determined as 420–475 °C and 0.01–0.022 s−1, in which a stable flow and a higher power dissipation were achieved.

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