Investigation of the effects of opening size and location on punching shear resistance of flat slabs using Abaqus

The paper presents a numerical study on the effects of opening size and location on punching shear resistance of flat slabs without drop panels and shear reinforcement using ABAQUS. The study proposes an ABAQUS model that is enable to predict the punching shear resistance of flat slabs with openings. The model is validated well with the experimental data in literature. Using the validated numerical model, the effects of opening size and location on the punching shear resistance of flat slabs are then investigated, and the numerical results are compared with those predicted by ACI 318-19 and TCVN 5574:2018. The comparison between experimental and numerical results shows that the ABAQUS model is reliable. The punching shear resistances calculated by ACI 318-19 and TCVN 5574:2018 with different opening sizes and locations are agreed well to each other, since the design principles between two codes now are similar.

Dependency of critical damping on various parameters of tapered bidirectional graded circular plates rested on Hetenyi medium

In industrial machinery and automobiles the critical damping plates are used as shock absorbers to dampen system and return rest position, in the shortest period of time. The paper is focused on the effects of various parameters on critical damping of a complicated system including a tapered bidirectional graded circular plate subjected to radially variable in-plane pre-load and rested on visco-Hetenyi elastic medium with semi-rigid restraint. By employing a Chebyshev-Ritz method, dependency of critical damping is investigated for the first time on various parameters including bidirectional arbitrary material gradation, variable in-plane pre-load, Hetenyi elastic medium parameters, tapering, semi-rigid restraint and Poisson’s ratio. For the Chebyshev-Ritz method developed here, the proper scale factor and orthogonal shifted Chebyshev polynomials of the first kind without auxiliary function requirement are used. The conventional rule of mixture and Mori-Tanaka homogenization scheme are used to model transverse gradation. The characteristic equation is calculated by vanishing determinant of the total potential energy Hessian. An equivalent ABAQUS model is introduced to eliminate necessity of complicated modeling of original structure.

New Standard Floor Assemble Simulation Approach for Abaqus Building Structures

The mechanical analysis of integral building structure needs the proper ABAQUS finite element analysis, but due to the ABAQUS software function limits the building structure modelling is a great workload and how to model integral structure more quickly and efficiently become a difficult problem. To reduce the workloads in ABAQUS analysis of integral structure models, the new ABAQUS standard floor assemble modelling approach and the program computational algorithm were proposed based on ABAQUS model data structure, nodes geometry transformation and horizontal surface coordinate value distinguish rule. Afterward one example engineering structure model using this standard floor assemble approach and the linear perturbation analysis were completed. The lateral displacement distribution from analysis indicated that each floor lateral displacements distributed continuously without any significant mutation and the standard floor assemble model can successfully achieve the continuous connection of the upper and the lower floors. By comparing the results of ABAQUS standard floor assemble model with that from PKPM SATWE analysis, it is proved that the ABAQUS standard floor assemble modelling is more accurate and can be applied in structure analysis.

Experimental and Numerical Analysis of FRCM Strengthened Parabolic Tuff Barrel Vault

This work focuses on an experimental and numerical study of a tuff barrel vault first damaged by differential vertical settlements of the abutments without rotations, then reinforced with a FRCM system composed by a fiber-reinforced mortar embedding a basalt fiber net, and finally subjected to a concentrated load on a generatrix (still ongoing). The geometry of the vault (polycentric near parabolic shape) and the masonry material (Apulian tuff) have been chosen in order to be representative of some masonry vaults common in rural constructions of Apulia region; also, a load representative of the infill weight has been applied during all the experimental tests. In parallel to the experiments, numerical simulations by a heterogeneous FE Abaqus model calibrated on the experimentally determined mechanical properties of materials have been performed. This model aims at reproducing the settlement phase and to accurately predict the load bearing capacity of the reinforced structure. To this aim, Concrete Damage Plasticity model has been used for modeling mortar joints and cementitious matrix, whereas tuff bricks have been assumed linearly elastic; finally, the basalt fiber net used in the FRCM reinforced has been described by suitable equivalent elasto-damaging trusses.

Investigation of rock bolting for tunnels based on an efficient CATIA-ABAQUS model

As a widely used reinforcement method in tunnel engineering, the accuracy of models in numerical analysis has a vital influence on the reliability of the analysis results. To solve the problem of hard modeling for complicated models, this paper proposes to build models of different characteristics automatically by the means of Enterprise Knowledge Language (EKL) of CATIA, combining knowledge engineering template with parameterization. Furthermore, the stability of surrounding rocks and the distribution features of plastic areas were studied in different cases by CATIA-ABAQUS model. Besides, the effects and contributions of several parameters, including the rock-bolt diameter and interval between rock-bolts have been studied. It was found that: (1) Rock-bolt has a notable effect on the stability of the surrounding rocks. Increasing the diameter of rock-bolts contributes to significantly reduce the plastic area and the vertical displacement. With the increase of the quantity and the diameter of anchors, the degree of influence gradually weakens, showing the logarithmic relationship; (2) When the quantity and diameter of rock-bolts are constant, in the case in which the intervals between rock-bolts are various, the plastic area of surrounding rocks and the axial stress of rock-bolts are larger than that of the same distance, while the vertical displacement are uniform. (3) The excavation process has a great influence on the axial stress of rock-bolts and the redistribution of stresses in the surrounding rock.

Prediction of Mechanical Properties of ERW Pipes Considering Manufacturing Process Through Numerical Analysis

Along with the development of the energy industry, demand for oil and gas pipelines has increased, and as the low oil price era has been prolonged, more economical pipe design and construction are required. Especially, ERW pipe has been expanding its range of applications, which is advantageous in terms of productivity and price. ERW pipes are made by passing through continuous rollers, where unintentional plastic deformation such as the Bauschinger effect occurs. Since plastic deformation caused by repetitive loading and unloading changes the initial properties of steel, it is necessary to precisely predict the final properties of the pipe as well as an accurate understanding of the manufacturing process. So, this study focused on evaluating the effects of manufacturing process considering plastic deformation for high performance ERW pipe manufacturing. In this paper, three manufacturing process stages of ERW pipe were simulated as 3D nonlinear finite element models using ABAQUS: forming stage, sizing stage, and flattening stage. And the ABAQUS model was verified by comparison with the outer diameter measured from full-scale size pipes. In order to maintain the continuity of analysis between each manufacturing process stage, PEEQ, Alpha and residual stress were obtained from each manufacturing process stage, and then these mechanical properties were mapped to the next manufacturing process stage. And change of mechanical properties during the each manufacturing process stage were examined. Finally, the change of material properties at the flattening stage where reverse bending occurs was evaluated, especially in influence of sizing ratio on the flattening stage. Through the developed analytical model, numerical prediction of the mechanical properties of ERW pipe is possible.

Numerical Analysis to Enhance Delamination Strength around Bolt Holes of Unidirectional Pultruded Large Smart Composite Platform

As a part of the DECID2 French National Project (2008–2012), construction of a large platform entirely made of smart composites was carried out and two demonstrators were installed. During a previous study, an ABAQUS model of smart composite platform was set up to perform numerical simulations that predict the mechanical behaviour of bolt-fastened platform under static three-point bending load, and a stress concentration is observed around the bolt holes. Unidirectional composites are subjected to delamination at very low stress, and this cannot be tolerated because most of the applications of pultruded structures are in civil engineering, which involves human safety. Therefore, it is essential to study the correlation of delamination onset and find a technology to enhance delamination strength. In this study, a numerical analysis was carried out to enhance the delamination strength around the bolt holes. Bidirectional fiberglass cloths were wrapped around unidirectional pultruded beams to reinforce the structure and to prevent delamination. Due to the high cost of these cloths, a study was also carried out to select an appropriate cloth material by taking into account two aspects: density and number of layers of cloths. The selected cloth was compared with conventional continuous fibreglass mat, and it was found that bidirectional fibreglass cloth material performs well in preventing delamination, even though it is expensive.

Numerical Simulation Analysis of Collapse Process of Isolated Structure in Strong Earthquakes

In this paper, the Abaqus model of an 8 layer isolation structure is established, and the connector element provided in the software is used to simulate the stiffness multilinearity in the horizontal and vertical direction of the isolation bearing. In the numerical analysis, six kinds of working conditions are set up to compare the vertical displacement, the peak acceleration and the interlayer displacement etc, and the effect of bearing failure on the superstructure is obtained.

Modal Analysis of High-Speed Parallel Manipulator with Flexible Links

The modal analysis was carried out to investigate the proposed improved curvature based finite element method (ICFE) for parallel manipulator with flexible links. The flexible link was discretizatied with ICFE first, and with the proposed rigid-flexible coupling technique, the flexible displacement of the moving platform and passive links was obtained, then through Lagrange equation, the structural model was derived. At last, to investigate the accuracy and efficiency of the ICFE and rigid-flexible coupling technique, modal analysis of ICFE model with different nodes and comparison studies with CFE and the ABAQUS model was carried out.