Nonlinear Analysis for the Crack Control of SMA Smart Concrete Beam Based on a Bidirectional B-Spline QR Method

A bidirectional B-spline QR method (BB-sQRM) for the study on the crack control of the reinforced concrete (RC) beam embedded with shape memory alloy (SMA) wires is presented. In the proposed method, the discretization is performed with a set of spline nodes in two directions of the plane model, and structural displacement fields are constructed by the linear combination of the products of cubic B-spline interpolation functions. To derive the elastoplastic stiffness equation of the RC beam, an explicit form is utilized to express the elastoplastic constitutive law of concrete materials. The proposed model is compared with the ANSYS model in several numerical examples. The results not only show that the solutions given by the BB-sQRM are very close to those given by the finite element method (FEM) but also prove the high efficiency and low computational cost of the BB-sQRM. Meanwhile, the five parameters, such as depth-span ratio, thickness of concrete cover, reinforcement ratio, prestrain, and eccentricity of SMA wires, are investigated to learn their effects on the crack control. The results show that depth-span ratio of RC beams and prestrain and eccentricity of SMA wires have a significant influence on the control performance of beam cracks.

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Substructure-Based Topology Optimization for Symmetric Hierarchical Lattice Structures

Symmetry ◽

10.3390/sym12040678 ◽

2020 ◽

Vol 12 (4) ◽

pp. 678

Author(s):

Zijun Wu ◽

Renbin Xiao

Keyword(s):

Topology Optimization ◽

High Efficiency ◽

Spline Interpolation ◽

Optimization Method ◽

Optimality Criteria ◽

Lattice Structures ◽

Hierarchical Lattice ◽

B Spline ◽

Design Variables ◽

Optimality Criteria Method

This work presents a topology optimization method for symmetric hierarchical lattice structures with substructuring. In this method, we define two types of symmetric lattice substructures, each of which contains many finite elements. By controlling the materials distribution of these elements, the configuration of substructure can be changed. And then each substructure is condensed into a super-element. A surrogate model based on a series of super-elements can be built using the cubic B-spline interpolation. Here, the relative density of substructure is set as the design variable. The optimality criteria method is used for the updating of design variables on two scales. In the process of topology optimization, the symmetry of microstructure is determined by self-defined microstructure configuration, while the symmetry of macro structure is determined by boundary conditions. In this proposed method, because of the educing number of degree of freedoms on macrostructure, the proposed method has high efficiency in optimization. Numerical examples show that both the size and the number of substructures have essential influences on macro structure, indicating the effectiveness of the presented method.

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Evaluation of water loss in transit and surface runoff in a Brazilian semi-arid basin

Ambiente e Agua - An Interdisciplinary Journal of Applied Science ◽

10.4136/ambi-agua.2545 ◽

2020 ◽

Vol 15 (4) ◽

pp. 1

Author(s):

Cristian Epifanio Toledo ◽

João Carlos Mohn Nogueira ◽

Alexandre De Amorim Camargo

Keyword(s):

Water Loss ◽

Surface Runoff ◽

High Efficiency ◽

Heterogeneous Environments ◽

Runoff Coefficient ◽

Water Losses ◽

Proposed Model ◽

Reservoir Basin ◽

In Transit ◽

Semi Arid

The objective of this work was to propose and evaluate a model to estimate transit water losses and surface runoff in a Brazilian semi-arid basin, fundamental components in the hydrological studies of the region, such as in the verification of hydrological connectivity. The study area was the Orós Reservoir Basin, located in the state of Ceará. The modeling of transit water loss and surface runoff were developed based on the work of Araújo and Ribeiro (1996) and Peter et al. (2014). In the proposed model, the parameter of loss in transit (k) was estimated at 0.027 km-1 for a section of the river basin, and when simulated for other stretches it provided good flow results at the end of the stretch, obtaining an NSE of 82%. The value of the runoff coefficient was estimated at 3% and when evaluating a spatial variation of this coefficient in the basin, the values varied from 2% to 12%, and the use of specialized runoff coefficient (RC) values promoted a higher NSE in the discharge simulation in the basin. It is concluded that the proposed model to estimate transit water losses and surface runoff demonstrated a high efficiency in the simulation of hydrological processes. The basin of Orós reservoir presented a high variability of the coefficient of surface runoff, justifying the need for a greater spatiality of this coefficient in heterogeneous environments.

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Influence of Patching on the Shear Failure of Reinforced Concrete Beam without Stirrup

Infrastructures ◽

10.3390/infrastructures6070097 ◽

2021 ◽

Vol 6 (7) ◽

pp. 97

Author(s):

Stefanus Adi Kristiawan ◽

Halwan Alfisa Saifullah ◽

Agus Supriyadi

Keyword(s):

Reinforced Concrete ◽

Shear Failure ◽

Numerical Study ◽

Unsaturated Polyester ◽

Reinforced Concrete Beam ◽

Concrete Cover ◽

Shear Capacity ◽

Rc Beam ◽

Shear Span ◽

Shear Cracking

Deteriorated concrete cover, e.g., spalling or delamination, especially when it occurs at the web of a reinforced concrete (RC) beam within the shear span, can reduce the shear capacity of the beam. Patching of this deteriorated area may be the best option to recover the shear capacity of the beam affected. For this purpose, unsaturated polyester resin mortar (UPR mortar) has been formulated. This research aims to investigate the efficacy of UPR mortar in limiting the shear cracking and so restoring the shear capacity of the deteriorated RC beam. The investigation is carried out by an experimental and numerical study. Two types of beams with a size of 150 × 250 × 1000 mm were prepared. The first type of beams was assigned as a normal beam. The other was a beam with a cut off in the non-stirrup shear span, which was eventually patched with UPR mortar. Two reinforcement ratios were assigned for each type of beams. The results show that UPR mortar is effective to hamper the propagation of diagonal cracks leading to increase the shear failure load by 15–20% compared to the reference (normal) beam. The increase of shear strength with the use of UPR mortar is consistently confirmed at various reinforcement ratios.

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Numerical approximation for the solution of linear sixth order boundary value problems by cubic B-spline

Advances in Difference Equations ◽

10.1186/s13662-019-2385-9 ◽

2019 ◽

Vol 2019 (1) ◽

Cited By ~ 5

Author(s):

A. Khalid ◽

M. N. Naeem ◽

P. Agarwal ◽

A. Ghaffar ◽

Z. Ullah ◽

...

Keyword(s):

Numerical Approximation ◽

Analytic Solution ◽

Linear Equations ◽

Computational Cost ◽

Spline Method ◽

System Of Linear Equations ◽

Approximation Solution ◽

B Spline ◽

Novel Technique ◽

Derivatives Of

AbstractIn the current paper, authors proposed a computational model based on the cubic B-spline method to solve linear 6th order BVPs arising in astrophysics. The prescribed method transforms the boundary problem to a system of linear equations. The algorithm we are going to develop in this paper is not only simply the approximation solution of the 6th order BVPs using cubic B-spline, but it also describes the estimated derivatives of 1st order to 6th order of the analytic solution at the same time. This novel technique has lesser computational cost than numerous other techniques and is second order convergent. To show the efficiency of the proposed method, four numerical examples have been tested. The results are described using error tables and graphs and are compared with the results existing in the literature.

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A proposed model for nonlinear analysis of RC beam-column joints under seismic loading

Engineering Structures ◽

10.1016/j.engstruct.2018.09.068 ◽

2019 ◽

Vol 180 ◽

pp. 829-843 ◽

Cited By ~ 8

Author(s):

Wentong Zhao ◽

Hong Yang ◽

Jinfeng Chen ◽

Panxu Sun

Keyword(s):

Nonlinear Analysis ◽

Seismic Loading ◽

Rc Beam ◽

Proposed Model

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Analysis of Crack Patterns of 500MPa Reinforced Concrete Beams

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.790.120 ◽

2013 ◽

Vol 790 ◽

pp. 120-124

Author(s):

Zhi Hua Li ◽

Xiao Zu Su

Keyword(s):

Static Loading ◽

Crack Width ◽

Concrete Beams ◽

Concrete Cover ◽

Reinforced Concrete Beams ◽

Crack Control ◽

Crack Patterns ◽

Beam Depth ◽

Steel Bars ◽

Constant Moment

Fourting concrete beams reinforced with 500MPa longitudinal steel bars, of which 6 with skin reinforcement and 8 without skin reinforcement, were tested under two-point symmetrical concentrated static loading to investigate their crack patterns. Crack distributions in constant moment region of beams are compared. The propagation of side cracks along the beam depth is obtained. The results of this study indicate that the concrete cover of longitudinal tensile steel bars and the spacing of skin reinforcement has significant effect on crack distributions; substantial crack control in beams can be achieved if the spacing of skin reinforcement is limited to certain critical values. The curve of d-w(d is the distance between observation points of side cracks and tension face of beams, w refers to crack width at observation points) is approximately characterized by a zig-zag shape and concave-left near longitudinal tensile steel bars.

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Topology Optimization and Performance Calculation for Control Arms of a Suspension

Advances in Mechanical Engineering ◽

10.1155/2014/734568 ◽

2014 ◽

Vol 6 ◽

pp. 734568 ◽

Cited By ~ 1

Author(s):

Liang Tang ◽

Jie Wu ◽

Jinhao Liu ◽

Cuicui Jiang ◽

Wen-Bin Shangguan

Keyword(s):

Topology Optimization ◽

Ride Comfort ◽

Constitutive Law ◽

Fea Model ◽

Proposed Model ◽

Rubber Bushing ◽

And Performance ◽

Motion Characteristics ◽

Ball Joints ◽

Performance Calculation

Control Arm (CA) of a suspension plays an important role in the automotive ride comfort and handling stability. In this paper, the topology optimization model including ball joints and bushing for topology optimization of an aluminium CA is established, where a ball joint is simplified as rigid elements and the elastic properties of a rubber bushing are estimated using Mooney-Rivlin constitutive law. A method for treating with multiple loads in topology optimization of CA is presented. Inertia relief theory is employed in the FEA model of the CA in order to simulate the large displacement motion characteristics of the CA. A CA is designed based on the topology optimization results, and the strength, natural frequency, and rigidity of the optimized CA are calculated. The calculated results show that the performances of the optimized CA with the proposed model meet the predetermined requirements.

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