Minimum vertical load on masonry walls - a realistic view / Mindestauflast auf Mauerwerkswänden - eine realitätsnahe Betrachtung

Mauerwerk ◽  
2015 ◽  
Vol 19 (4) ◽  
pp. 245-257 ◽  
Author(s):  
Michael Schmitt ◽  
Carl-Alexander Graubner ◽  
Valentin Förster
2021 ◽  
Vol 13 (21) ◽  
pp. 11647
Author(s):  
Mohammed Deyazada ◽  
Hervé Degée ◽  
Bram Vandoren

Since energy efficiency has become the main priority in the design of buildings, load-bearing walls in modern masonry constructions nowadays include thermal break elements at the floor–wall junction to mitigate thermal bridges. The structural stability of these bearing walls is consequently affected. In the present paper, a numerical study of the resistance and stability of such composite masonry walls, including AAC thermal break layers, is presented. A finite element mesoscopic model is successfully calibrated with respect to recent experimental results at small and medium scale, in terms of resistance and stiffness under vertical load with or without eccentricity. The model is then used to extend the numerical models to larger-scale masonry walls made of composite masonry, with the aim of investigating the consequences of thermal elements on global resistance and stability. The results confirm that the resistance of composite walls is governed by the masonry layer with the lowest resistance value, except for walls with very large slenderness and loaded eccentrically: composite walls with low slenderness or loaded by a vertical load with limited eccentricities are failing due to the crushing of the AAC layer, while the walls characterized by large slenderness ratios and loaded eccentrically tend to experience buckling failure in the main clay masonry layer.


2021 ◽  
Author(s):  
Guangli Du ◽  
Thomas Cornelius ◽  
Joergen Nielsen ◽  
Lars Zenke Hansen

<p>Structural modelling of a masonry wall is challenging due to material properties, eccentricity of the vertical load, slenderness ratio etc. In recent theoretical developments for design of masonry walls, a new “Phi” method to determine the eccentricity is adopted in Eurocode 6. However, the comparisons between this method and the conventional “Ritter” method shows that for certain prerequisites it would result in substantial different load-bearing capacity. Hence, in order to investigate how support conditions influence the load bearing capacity of the wall, this study performs a nonlinear numerical analysis of a wall for several load cases in ABAQUS and the result is verified with an independently developed calculation tool using MATLAB. The results show that the top rotation plays a significant role for the load bearing capacity of the masonry wall supported by slabs at both ends. It is difficult to estimate the eccentricities without a rigorous calculation.</p>


2011 ◽  
Vol 94-96 ◽  
pp. 406-415 ◽  
Author(s):  
Yan Huang ◽  
Ming Hui Kan ◽  
Zi Fa Wang

Abstract: Confined masonry with tie columns and ring-beams was adopted during the reconstruction in the rural and suburban areas in Sichuan Province after the 2008 Wenchuan Earthquake. Based on the results of the sample tests of building material such as clay brick, cement mortar, steel and concrete in reconstruction and the analysis on the characteristics and features using Solid65 elements in ANSYS, the shear property of joints in masonry structures under different vertical load (σ∕fm) is numerically simulated. Comparing the experimental results with the numerical ones, the proposed values for the shear transfer coefficients for open and closed crack of Solid65 elements for simulating masonry structures are given. The seismic performance of confined masonry walls (strengthened by tie column and ring-beam, etc.) and unconfined masonry walls with different stress condition (σ∕fm) under low cyclic load are discussed. Results show that, under monotonic loading, confined masonry walls have better performance for displacement and load corresponding to the occurrence of the first crack as well as for the ultimate load and ductility, although the energy dissipating ability of unconfined walls under low cyclic loading increases with vertical load (σ∕fm) at low stress level. The results demonstrate that confined walls are greatly enhanced by strengthening measures such as tie column and ring-beams.


Author(s):  
Jure Radnić ◽  
Marija Smilović ◽  
Alen Harapin ◽  
Nikola Grgić ◽  
Ante Buzov

2020 ◽  
Vol 19 (3) ◽  
pp. 127-141
Author(s):  
Adam Piekarczyk

The paper presents selected results of tests of full-scale masonry walls linearly supported on a deflecting beam. The walls with thin bed joints and unfilled head joints were 4.55 m long and 2.45 m high, and were made of group 1 calcium silicate masonry units. The tests included walls with and without openings. The tests were carried out in a specially designated and constructed test stand, which allowed simultaneous vertical load on the upper edge of the wall and vertical deflection of the beam supporting this wall. During the test, measurements of mutual displacements of six points on the wall surface were carried out. On both faces of masonry specimens, the changes of the length of the measuring bases connecting these six points were recorded. Walls without openings were detached from the central part of the supporting beam at a deflection not exceeding 2 mm. Walls with one door opening also cracked at an early stage of tests. In this case, a detachment from the supporting beam and cracking at the ends of the lintel occurred because of the rotation of the pillars connected by the lintel above the opening. In walls with two door openings, first cracks were formed at the ends of lintels due to the rotation of pillars with a small deflection of the supporting beam, less than 3 mm. Whereas, in walls with door and window openings, first cracks occurred under the window and at the end of the lintel in the outer pillar of the wall.


2021 ◽  
Vol 1203 (2) ◽  
pp. 022031
Author(s):  
Radosław Jasiński

Abstract Verification of shear load capacity is required for all shear walls that take horizontal wind loads, loads imposed by ground action or other non-mechanical (rheological or thermal) loads. Shear walls are exposed not only to shear forces, but also vertical actions caused by dead load or imposed loads as shear walls also usually function as bearing walls. This load combination is quite important as shear load capacity V Rd depends on mean design stresses σd which, in turn, depend on design forces N Ed. Interactions between shear V Rd and vertical load N Ed in shear walls are the consequence of observed combinations of actions in these types of walls. Additionally, the vertical load N Ed acts on the wall at certain eccentricity eEd, which can result in a change in the length of the compressed part of the cross-section l c. This paper describes the procedure for verifying shear load capacity by means of the interaction diagram drawn as specified in Eurocode 6 (prEN 1996-1-1:2017). Necessary equations for determining load-carrying capacity of cross-section against vertical load N Ed were worked out. The effect of wall shape and eccentricity of vertical load on the shape of the interaction diagram was analysed.


2001 ◽  
Vol 29 (4) ◽  
pp. 258-268 ◽  
Author(s):  
G. Jianmin ◽  
R. Gall ◽  
W. Zuomin

Abstract A variable parameter model to study dynamic tire responses is presented. A modified device to measure terrain roughness is used to measure dynamic damping and stiffness characteristics of rolling tires. The device was used to examine the dynamic behavior of a tire in the speed range from 0 to 10 km/h. The inflation pressure during the tests was adjusted to 160, 240, and 320 kPa. The vertical load was 5.2 kN. The results indicate that the damping and stiffness decrease with velocity. Regression formulas for the non-linear experimental damping and stiffness are obtained. These results can be used as input parameters for vehicle simulation to evaluate the vehicle's driving and comfort performance in the medium-low frequency range (0–100 Hz). This way it can be important for tire design and the forecasting of the dynamic behavior of tires.


1977 ◽  
Vol 5 (2) ◽  
pp. 102-118 ◽  
Author(s):  
H. Kaga ◽  
K. Okamoto ◽  
Y. Tozawa

Abstract An analysis by the finite element method and a related computer program is presented for an axisymmetric solid under asymmetric loads. Calculations are carried out on displacements and internal stresses and strains of a radial tire loaded on a road wheel of 600-mm diameter, a road wheel of 1707-mm diameter, and a flat plate. Agreement between calculated and experimental displacements and cord forces is quite satisfactory. The principal shear strain concentrates at the belt edge, and the strain energy increases with decreasing drum diameter. Tire temperature measurements show that the strain energy in the tire is closely related to the internal temperature rise.


Sign in / Sign up

Export Citation Format

Share Document