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 Behavior of the T-Shaped Concrete-Filled Steel Tubular Columns after Elevated Temperature

2021 ◽  
Vol 2021 ◽  
pp. 1-20
Author(s):  
Xianglong Liu ◽  
Jicheng Zhang ◽  
Hailin Lu ◽  
Ning Guan ◽  
Jiahao Xiao ◽  
...  
Keyword(s):  
Elevated Temperature ◽  
Bearing Capacity ◽  
Failure Modes ◽  
Shear Failure ◽  
Element Model ◽  
Ultimate Bearing Capacity ◽  
Steel Tubes ◽  
Tubular Columns ◽  
Short Columns ◽  
Experimental Values

The mechanical properties of T-shaped concrete-filled steel tubular (TCFST) short columns under axial compression after elevated temperature are investigated in this paper. A total of 30 TCFST short columns with different temperature (T), steel ratio (α), and duration of heating (t) were tested. The TCFST column was directly fabricated by welding two rectangular steel tubes together. The study mainly investigated the failure modes, the ultimate bearing capacity, the load-displacement, and the load-strain performance of the TCFST short columns. Experimental results indicate that the rectangular steel tubes of the TCFST column have deformation consistency, and the failure mode consists of local crack, drum damage, and shear failure. Additionally, the influence of high temperature on the residual bearing capacity of the TCFST is significant, e.g., a higher temperature can downgrade the ultimate bearing capacity. Finally, a finite element model (FEM) is developed to simulate the performance of the TCFST short columns under elevated temperature, and the results agree with experimental values well. Overall, this investigation can provide some guidance for future studies on damage assessment and reinforcement of the TCFST columns.

scholarly journals Displacement Study of a Large-Scale Freeform Timber Plate Structure Using a Total Station and a Terrestrial Laser Scanner

Sensors ◽  
2020 ◽  
Vol 20 (2) ◽  
pp. 413 ◽  
Author(s):  
Anh Chi Nguyen ◽  
Yves Weinand
Keyword(s):  
Large Scale ◽  
Numerical Models ◽  
Laser Scanner ◽  
Experimental Tests ◽  
Point Clouds ◽  
Element Model ◽  
Experimental Investigations ◽  
Bottom Surface ◽  
Terrestrial Laser Scanner ◽  
Total Station

Recent advances in timber construction have led to the realization of complex timber plate structures assembled with wood-wood connections. Although advanced numerical modelling tools have been developed to perform their structural analysis, limited experimental tests have been carried out on large-scale structures. However, experimental investigations remain necessary to better understand their mechanical behaviour and assess the numerical models developed. In this paper, static loading tests performed on timber plate shells of about 25 m span are reported. Displacements were measured at 16 target positions on the structure using a total station and on its entire bottom surface using a terrestrial laser scanner. Both methods were compared to each other and to a finite element model in which the semi-rigidity of the connections was represented by springs. Total station measurements provided more consistent results than point clouds, which nonetheless allowed the visualization of displacement fields. Results predicted by the model were found to be in good agreement with the measurements compared to a rigid model. The semi-rigid behaviour of the connections was therefore proven to be crucial to precisely predict the behaviour of the structure. Furthermore, large variations were observed between as-built and designed geometries due to the accumulation of fabrication and construction tolerances.

Analysis of Bending Loads on Bamboo-Balsa and Bamboo-Polypropylene Honeycomb Composite Sandwiches

2015 ◽  
Vol 1125 ◽  
pp. 94-99 ◽  
Author(s):  
Aldyandra Hami Seno ◽  
Eko Koswara ◽  
Hendri Syamsudin ◽  
Djarot Widagdo
Keyword(s):  
Failure Modes ◽  
Shear Failure ◽  
Numerical Models ◽  
Future Research ◽  
Test Results ◽  
Bending Tests ◽  
Bending Loads ◽  
Bending Behavior ◽  
Honeycomb Cores ◽  
Load Deflection Curve

This research was done to evaluate the bending behavior (load-deflection curve and failuremode) of sandwich structures using Tali Bamboo strips as sandwich skin material. Bending tests wereconducted on sandwich specimens with end grain balsa (3-point bending) and polypropylene (PP)honeycomb cores (4-point bending) to evaluate their bending behavior. From the test results,analytical and numerical models were developed to simulate the observed bending behavior. Themodels are able to simulate the pre-failure bending behavior and failure modes (core shear failure) ofthe specimens. It is also shown that for thin (length/thickness > 20) sandwiches the models are moreaccurate since shear effects are less prominent. With the obtained models a predictive comparison isdone between the PP and balsa cored specimens since the testing configuration for each type wasdifferent. The analysis results show that balsa cored specimens are able to withstand higher transversebending loads due to the higher shear strength of the balsa core. These prediction results are to beproven by specimen testing which is the subject of future research.

scholarly journals A Design Method to Induce Ductile Failure of Flexural Strengthened One-Way Reinforced Concrete Slabs

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7647
Author(s):  
Huy Q. Nguyen ◽  
Tri N. M. Nguyen ◽  
Do Hyung Lee ◽  
Jung J. Kim
Keyword(s):  
Reinforced Concrete ◽  
Failure Modes ◽  
Shear Failure ◽  
Design Method ◽  
Concrete Slab ◽  
Ductile Failure ◽  
Reinforced Concrete Slabs ◽  
Failure Loads ◽  
Ultimate Failure ◽  
Rc Slabs

Strengthening existing reinforced concrete (RC) slabs using externally bonded materials is increasingly popular due to its adaptability and versatility. Nevertheless, ductility reduction of the rehabilitated flexural members with these materials can lead to brittle shear failure. Therefore, a new approach for strengthening is necessary. This paper presents a methodology to induce ductile failure of flexural strengthened one-way RC slabs. Ultimate failure loads can be considered to develop the proposed design methodology. Different failure modes corresponding to ultimate failure loads for RC slabs are addressed. Flexural and shear failure regions of RC slabs can be established by considering the failure modes. The end span of the concrete slab is shown for a case study, and numerical examples are solved to prove the essentiality of this methodology.

Limit States for Deepwater Flowlines and Risers: Review of the Research Activities at the Submarine Technology Laboratory/COPPE

2003 ◽  
Author(s):  
S. F. Estefen ◽  
T. A. Netto ◽  
I. P. Pasqualino
Keyword(s):  
Ultimate Strength ◽  
Large Scale ◽  
Failure Modes ◽  
Numerical Models ◽  
Experimental Tests ◽  
Limit States ◽  
Collapse Pressure ◽  
Research Activities ◽  
Structural Resistance ◽  
Buckle Arrestors

Research activities related to the limit states of flowlines and risers conducted at the Submarine Technology Laboratory / COPPE in cooperation with PETROBRAS are presented. The motivation for most of the research programs is associated with deepwater challenges arising from the rigid pipe installations at Campos Basin. Initially ultimate strength of intact pipes are investigated together with aspects related to residual strength, buckling propagation and buckle arrestors. Based on the experimental results numerical models have been correlated in order to be used to generate results for full scale steel pipes. Ultimate strength curves have been then produced as well as the analytical equation representative of these curves. Experimental tests of buckling propagation for small and large scale pipes have also been performed to obtain the bias factor for different equations proposed in the literature. Based on this study an equation for propagation pressure has been recommended. In addition, ring and cylinder buckle arrestors have been tested in order to propose an expression relating crossing over pressure with the arrestor geometries. An overview of the studies aiming at establishing the influence of the reeling method of installation on the failure modes of flowlines and steel catenary risers is presented. It is emphasized the influence of cross-section ovality and weld defect amplification due to plastic bending on collapse pressure and fatigue life, respectively. Finally, the development of a new concept of sandwich pipe for ultra deepwater, combining structural resistance and thermal insulation is discussed.

Assessment of the Realistic Stiffness and Capacity of the Connections in Quincha Frames to Develop Numerical Models

2013 ◽  
Vol 778 ◽  
pp. 526-533 ◽  
Author(s):  
Natalie Quinn ◽  
Dina D’Ayala
Keyword(s):  
Finite Element ◽  
Numerical Models ◽  
Experimental Tests ◽  
Element Model ◽  
Accurate Representation ◽  
Timber Frame ◽  
Historic Structures ◽  
The World ◽  
Infill Material ◽  
High Degree

Peru is one of the most seismically active countries in the world, this fact highlighted by several destructive earthquakes in recent years. The centre of Lima has a large number of historic structures with a ground floor in adobe, and their upper storeys in quincha, a traditional technique consisting of a timber frame with an infill of canes and mud. Despite the existence of a large number of buildings containing this technique, very little is known about its seismic performance. In order to investigate this, a series of experimental tests on quincha frames, with and without the infill, have been carried out previously, with the aim of quantifying the lateral behaviour and identifying vulnerable areas. The present paper details work carried out to develop a finite element model of the test frames without infill. This model of the timber frame will enable an accurate representation of the frame behaviour to be developed before adding the infill of canes and mud to the model. As the behaviour of the infill material and its connection to the frame is difficult to determine, characterising the timber frame with a high degree of accuracy ensures that the contribution of the infill can be globally quantified from the overall experimental results. The beams and posts are connected by cylindrical mortice and tenon joints, with a diagonal bracing member providing some lateral restraint. The connections have been modelled semi-rigid springs, with the stiffness calculated using variations of the component method. This was found to give very similar results to those obtained experimentally.

Portal Frames with a Novel Cold-Formed Tapered Box-Section

2018 ◽  
Vol 763 ◽  
pp. 301-309
Author(s):  
Amir Shahmohammadi ◽  
James B.P. Lim ◽  
George Charles Clifton
Keyword(s):  
Failure Modes ◽  
Numerical Models ◽  
Experimental Testing ◽  
Design Procedure ◽  
Torsional Stiffness ◽  
Food Storage ◽  
Analysis And Design ◽  
Portal Frame ◽  
Frame System ◽  
Lateral Bracing

This paper introduces a novel steel portal frame system, in which cold-formed nested tapered box members are used in the design. The bird and dust proofing features of the system make it useful for applications where clean work areas are required, such as food, storage, and manufacturing industries. The new section used in the portal frames comprises two cold-formed channels welded to each other, forming a box-shaped steel member, either tapered or prismatic along its length. Such sections possess high torsional stiffness compared with the conventional I-sections; therefore, lateral bracing employed for the flexural-torsional buckling suppression of I section portal frames is mostly unnecessary. A comparative study, taking into account the cost of steel, painting, bird proofing and lateral bracing, is conducted between a number of portal frames with the proposed box-sections and the conventional I-sections. An analysis and design code, incorporating the Genetic Algorithm (GA), is developed to optimise the weight of the designed frames. The results indicate that the novel portal frame system is economically viable with additional benefits of bird and dust proofing. To investigate the failure modes and verify design procedure of the new portal frame, an experimental testing program is undertaken in University of Auckland. The test results show excellent behaviour and good agreement with the numerical models but have been completed too recently to be included in this paper.

Numerical Simulation of Polyurethane Strengthened Perforated Masonry Walls under Blast Loading

2013 ◽  
Vol 639-640 ◽  
pp. 727-731
Author(s):  
Yu Rong Guo ◽  
Hong Zheng
Keyword(s):  
Numerical Simulation ◽  
Failure Modes ◽  
Numerical Models ◽  
Time History ◽  
Local Failure ◽  
Masonry Walls ◽  
Layer Number ◽  
Failure Patterns ◽  
Resistance Performance ◽  
Strengthening Method

In order to investigate the explosion resistance performance of perforated masonry walls strengthened with polyurethane, nine numerical models with different layer number and different strip width of polyurethane are established in this paper. Deformation drawings and time history curves of displacement of the numerical models are comparatively analyzed. It is found that there are two failure modes, global failure and local failure, of strengthened masonry walls and the differences of failure patterns are significant between various types of strengthening method.

Structural Behaviour of Historical Stone Arches and Vaults: Experimental Tests and Numerical Analyses

2014 ◽  
Vol 628 ◽  
pp. 43-48 ◽  
Author(s):  
Marco Bovo ◽  
Claudio Mazzotti ◽  
Marco Savoia
Keyword(s):  
Mechanical Response ◽  
Numerical Solutions ◽  
Experimental Tests ◽  
Element Model ◽  
Seismic Effect ◽  
Structural Behaviour ◽  
In Situ Tests ◽  
Different Types ◽  
Non Linear ◽  
Stone Arches

Recent seismic events showed the dramatic need, especially in case of historical and existing buildings, of important strengthening activities to be carried out. In order to properly design them, a careful assessment of real structural behaviour and load-carrying capacity of these buildings is strongly required. This is particularly important when dealing with constructions made of heterogeneous materials like masonry or stonework, where often conventional analysis techniques do not behave satisfactorily. This paper presents the results of an extensive experimental and numerical investigation on historical stone arches and vaults. A series of in-situ tests were carried out on different types of stone arches belonging to a large building of the XIX century, with the purpose of investigating their mechanical response and obtaining the structural behaviour of stonework under different types of in-plane loads. The experimental results were compared with the numerical solutions obtained by a detailed finite element model of a portion of the structure. Numerical linear and non-linear FE analyses were conducted in order to reproduce the experimental tests and analyse the interaction between series of arches that are linked by cross vault or tunnel vault. Finally, non-linear analyses with vertical and horizontal loads were carried out with the scope of simulating the seismic effect and to verify the ductility of this type of vaulted structures.

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