Reinforcement Patterns Research Articles

Stability of expansive soil slopes reinforced with anchor cables based on rotational-translational mechanisms

Expansive soil slopes are usually characterized with conspicuous fissures. Pre-stressed anchor cables are effective techniques in improving the slope stability. Explicit considerations of the fissures and the suction effect become crucial in producing more realistic solutions. Based on the kinematic limit analysis theorem, this paper performs a limit analysis of the stability for expansive soil slopes stabilized by anchor cables. The upper bound solution to the slope stability was optimized and compared with the published solutions, demonstrating the applicability of the proposed method. An illustrative slope reinforced with two different reinforcement patterns was investigated to show the role of soil suction and anchor reinforcement in the safety assessments of expansive soil slopes. The results indicate that the slope stability and anchor reinforcement relate closely to the fissures. A threshold value of the fissure height exists, beyond which the slope stability is significantly reduced. An optimum inclination angle (ξopt) of anchors exists universally and is reduced as the anchor height, the internal friction angle and the surcharge load increase.

Experimental Study of Infill Walls with Joint Reinforcement Subjected to In-Plane Lateral Load

The results of an experimental study of four infilled frames with brick masonry walls subject to reversal cyclic lateral load are presented. The variables studied were the height to length aspect ratio of the wall and the use of joint reinforcement. The investigation was motivated by the fact that the Mexican code establishes the same specifications about the use of joint reinforcement for infill walls as for confined walls, because there is not enough experimental evidence on joint reinforced infill walls. To investigate the possible interaction of the study variables in the seismic performance of the walls, two pairs of specimens, scaled 1:2, with different aspect ratios (H/L = 0.75, 0.41) were tested. The specimens in each pair were identical except that one of them included steel bars into the bed-joints as reinforcement leading to amount phfyh=0.6 MPa. The infill walls with H/L = 0.41 were included from a previous study. The behavior of the specimens was defined in terms of lateral strength, ductility, displacement capacity, deformation of the joint reinforcement and crack pattern. The results indicate that joint reinforcement increases the strength of the system; however, the increase was more pronounced in longer walls. Ductility was reduced with horizontal reinforcement and this behavior was more important for longer walls. As occurred in confined walls, the joint reinforcement generates a more distributed cracking and reduces the width of the cracks. The experiments are described and this and other results are discussed in detail.

Study of the Effects of Compaction and Split Grouting on the Structural Strengthening Characteristics of Weakly Cemented Argillaceous Rock Masses

There is a wide distribution of weakly cemented argillaceous rock masses in areas where there are many coal mines, and their complex characteristics make them more difficult to support. This paper researches this type of rock and studies the slurry diffusion mechanism and grouting reinforcement characteristics of injected rock mass and their relationship with compaction and splitting grouting. The grouting mode is dominated by compaction and splitting. The rheological behavior of cement slurries with different concentrations used in split grouting was studied. The existing grouting equipment was improved, and grouting tests were performed on loose aggregates of weakly cemented primary rock in a certain size range. Subsequently, basic physical parameter determination tests, microscopic tests, and uniaxial tests were performed on grout, and the effects of grouting pressure, moisture content of standard samples, slurry water/cement ratio, and curing time on grouting reinforcement were analyzed. During the grouting process, the pattern of plasma pulse diffusion and reinforcement was summarized as three types: compaction, splitting, and microcracking. The failure modes of rock were summarized as shear failure, shear failure along the interface of the plasma, and splitting damage.

Functional analysis patterns of automatic reinforcement: A review and component analysis of treatment effects.

Functional analysis (FA) conditions include different antecedent or consequent events that may disrupt responding. Thus, varying patterns of FA differentiation may predict treatment outcomes of problem behavior maintained by automatic reinforcement. These patterns could be used to inform the development of individualized interventions. An approach to classifying these patterns is to categorize FA outcomes as attention condition lowest, demand condition lowest, and play condition lowest, according to the condition in which problem behavior is most disrupted. In Study 1, we applied this criterion to 120 datasets finding that 60% could be classified using this method, whereas 89% of datasets showed a disruption of 50% or higher. In Study 2, we conducted a treatment component analyses for 3 individuals whose FAs each exhibited one of the 3 distinct patterns. The results indicated that specific elements of the FA conditions could reduce problem behavior. The predictive utility of these disruption patterns is discussed.

Comparative Studies on the Behaviour of Flat Panels Made of GRP Under Static and Dynamic Loads

Glass reinforced plastic, so called GRP, is a composite material made of glass strands called fibbers woven together to create a flexible fabric. GRP is a lightweight material with many and diverse applications ranging from the manufacture of reservoirs for different liquids to the manufacture of boats, yachts, chairs and even children playground furniture. The behaviour of this material under static and dynamic loads is still raising interest from the scientific community and a large number of researchers. This continued interest is due to the material versatility for different applications depending on its manufacture process that has a significant weigh-in in the material mechanical properties. These resulting mechanical properties need to be carefully analysed and benchmarked prior to using the obtained material in commercial applications. The scope of this research study is to analyse the behaviour of glass reinforced plastic plate panel with reinforcements on one and two directions under static and dynamic loads employing both experimental and numerical methods for results validation. The methods used in this research study for the dynamic loads can also be applied successfully to other composite materials. Additionally, the stress plots have been analysed in iteration in order to ensure the most optimal reinforcement pattern.

Numerical models for analysis and adjustment of magnetic field in medical centers. I. Simulation of geomagnetic field disturbances

The study investigates possible disturbances of the Earth’s geomagnetic field associated with ferromagnetic structures of clinical buildings. An original methodology has been applied for 3D field mapping of hospital areas in the Senegalese Radiotherapy (RT) Centre. The RT unit will be located in a bunker with thick steel walls to ensure safety of patients and staff. Steel reinforcement will provide the shielding effect lowering the field level in the therapy room. A detailed numerical model has been created to simulate an expected field map in the RT bunker. The model reflects the actual geometry and reinforcement pattern of the building as well as adopted national standards for hypomagnetic field environment. The field maps generated with the EM codes KLONDIKE and KOMPOT form a basis for validation in comparative computations with the other codes (COMSOL Multiphysics, etc).

Influence of truss-type and welded reinforcement in concrete beam

In present study, the shear strength of the conventional reinforced concrete beam (here named as non-welded rectangular stirrup beam - NRSB) is compared with three types of beam having modified reinforcement patterns, named as welded rectangular stirrup beam (WRSB), non-welded Warren truss beam (NWTB) and welded Warren truss beam (WWTB). Such names are given based on the stirrup orientation. All beams have the same concrete dimension and the same total weight of reinforcement, ensuring no variation of cost. From the test results, the average shear strength enhancement of WRSB, NWTB, and WWTB was found to be more than 17%, 10%, and 30% compared with conventional NRSB. WWTB was proposed to be the best alternative. To design the above-mentioned beams, design equations are proposed and verified. Use of finite elemental software reveals that in reinforcement the stress intensity (Von-mises) is the maximum in WWTB, followed by WRSB, NWTB and finally NRSB.

Evaluation of the Sensitivity of Various Reinforcement Patterns for Structural Carbon Fibers to Open Holes during Tensile Tests.

This paper is devoted to the experimental study of polymeric composite specimens, with various types of reinforcement, in order to evaluate the breaking strength of specimens with open holes when undergoing uniaxial compression and tensile tests. Four types of interlaced 3D woven preforms were considered (orthogonal, orthogonal combined, with pairwise inter-layer reinforcement, and with pairwise inter-layer reinforcement and a longitudinal layer), with a layered preform used for comparison. Tensile tests of solid specimens without a hole, under ASTM D 3039, and of specimens with an open hole, under ASTM D 5766, were carried out using the Instron 5989 universal electromechanical testing system. Movements and strains on the specimen surface were recorded using a Vic-3D contactless optical video system and the digital images correlation method (DIC). For all the series of carbon fiber tension specimens, strain and stress diagrams, mechanical characteristics, and statistical processing for 10 specimens were obtained. The paper evaluated deformation fields for certain points in time; the obtained fields showed an irregular distribution of deformation and dependency on types of reinforcing fibers. A coefficient of strength variation is introduced, which is defined as a ratio of the ultimate stress limits obtained on solid samples with and without open holes. Within the framework of ASTM D 5766, when calculating the ultimate stress, the hole is not taken into account, and the paper shows that for certain structures a hole cannot be excluded. The hole size must not be neglected when calculating the ultimate stress.

Ultimate loads for reinforced concrete square pile caps

This paper reports the test results for eight high-strength concrete square pile caps. The main variables are the area of flexural steel bars and the configuration patterns of flexural steel bars. The test results show that the ultimate load on the pile cap increases as the total area of the flexural steel bars increases. The load–displacement curves are not significantly affected by an increase in the total area of the flexural steel bars. For a specific area of flexural steel bar, the ultimate load on the pile caps in a bunched square reinforcement pattern is no greater than that for pile caps in a grid reinforcement pattern. Pile caps in a bunched square reinforcement pattern exhibit no significant mechanical advantage over pile caps in a grid reinforcement pattern. Square pile caps in a grid reinforcement pattern perform better because this pattern is more conducive to concrete casting than a bunched square reinforcement pattern. The softened strut-and-tie model more accurately predicts the ultimate load for pile caps than the ACI sectional method for various shear span-to-depth ratios and compressive strengths of concrete. The ACI sectional method overestimates the flexural strength of the square pile cap.

On linear and nonlinear bending of functionally graded graphene nanoplatelet reinforced composite beams using Gram-Schmidt-Ritz method

The current study examined the linear and nonlinear bending results of functionally graded graphene nanoplatelet reinforced composite beams. The equation system was constructed using Reddy's third order shear deformation theory and a von Kármán type nonlinear strain-displacement relationship. The nonlinear bending results of this system were solved using the Gram-Schmidt-Ritz method in conjunction with the direct iteration technique. By employing the Gram-Schmidt orthogonalization procedure for generating shape functions in the method, numerically stable functions for nonlinear bending analysis of beams were obtained. Our solutions were validated for accuracy by comparing them to some published results. The numerical results indicate that the geometrical nonlinearity of beams subjected to uniform distributed load is greater than that of beams subjected to sinusoidal, linear, or parabolic distributed loads. New results on several significant effects of reinforcement patterns, graphene nanoplatelet weight fraction, and different types of distributed loads are presented and discussed in this study, in which the findings can serve as a benchmark for future research.

Numerical study on seismic performance improvement of composite wide beam-column interior joints

This study aims to improve the seismic performance of a post-tensioned precast wide U beam-column interior joint system, consisting of a precast column, a precast wide U beam as permanent formwork with post-tensioned and cast-in-situ concrete in the joint region, through a numerical approach. The numerical model was verified by simulating a tested half-scale precast wide U beam-column interior joint (PWUBCIJ) system. After the methodological validation, numerical analyses were performed for full-scale and modified wide beam-column joints subjected to lateral cyclic loading. The modified joint models were developed to eradicate or delay diagonal shear cracks and concrete crushing of the tested control specimen. Since the wide precast U beam-column joint system possesses typical and unique joint details, improvement in reinforcement detailing was performed by varying reinforcement patterns. Moreover, a study to reduce the number of A-truss rows was performed to optimize the numbers of A-trusses used. Therefore, a series of FE analyses are performed to elucidate the contribution of each parameter in enhancing the joint strength and drift capacity of the structure. Enhanced load capacity, increased energy dissipation, and higher ductility are achieved using transverse reinforcement and transverse tendons. This is considered due to the formation of the strut-and-tie mechanism, which results in a better force and moment transfer path and from the overall confinement of the system due to the presence of transverse steel and prestressing tendon. As per numerical results, the modified full-scale precast wide U beam-column interior joint was proved to be able for application in the highest seismic zone of Thailand.

Effect of elevated temperature on interfacial shear transfer capacity of self-compacting concrete

Interfacial shear stress transfer may occur in structural elements across concrete or between concrete and steel. The fundamental contributing parameters which improve the shear capacities are aggregate grading, compressive strength of concrete, type and area of the interfacial zone, and interfacial reinforcement pattern. During the event of a fire, these parameters are severely affected and mainly depend on the exposure level of the temperature and its duration. In the present investigation, the effect of elevated temperature on the interfacial Shear Transfer Capacity (STC) of Self-Compacting Concrete (SCC) was evaluated using shear (push-off) specimens. SCC was developed using Fly Ash (FA) and Ground Granulated Blast Furnace Slag (GGBFS) as Supplementary Cementitious Material (SCM). The study emphasises the proper understanding of degradation in shear strength of SCC exposed to elevated temperatures. Expanded Perlite Aggregate (EPA) is utilised as a partial replacement for fine aggregate. Also, a thermal protective coating is developed with Cement Perlite Plaster (CPP) for improving the performance of SCC. The European Federation of National Associations Representing for Concrete (EFNARC) guidelines were followed to ensure the workability of the developed SCC mix. Specimens were exposed to 30, 60, 90, and 120 min of heating durations following the International Organization for Standardization 834 (ISO 834) fire rating curve and tested to examine residual compressive strength, mass loss, STC after the natural air cooling process. The SCC specimens with EPA content have exhibited higher residual compressive strength and STC. All the protected SCC specimens coated with the CPP mixture contributed to retaining the original shear capacity by resisting the temperature. An empirical relationship was proposed to predict the residual STC of SCC after exposure to elevated temperature.

Comparing Performance of 3D-Printed and Injection-Molded Fiber-Reinforced Composite Parts in Ring-Spinning Traveler Application

Fiber-reinforced 3D printing (3DP) technology is a recent addition to the material extrusion-based 3DP process unlocking huge potential to apply this technology for high-performance material fabrication with complex geometries. However, in order to take the full advantage of this technology, a comparative analysis with existing technologies targeting a particular application is necessary to understand its commercial applicability. Here, an applied composite part, ring-spinning travelers, has been developed using the unique design features of fiber-reinforced 3DP technology that is beyond the capability of the currently used technology; the injection molding, quality, and performance of the printed and molded travelers were investigated and compared. The results demonstrated that fiber-reinforced 3DP is a promising technology that offers a lot of flexibility regarding reinforcement patterns and materials including both short and continuous fibers to tailor the performance, although the printed travelers showed poorer surface characteristics and wear resistance than the molded travelers. Based on the present analysis, a number of recommendations have been proposed on the design of the traveler to apply the technology effectively and use the printer to improvise and manipulate the performance of the travelers.

Hybrid autonomous controller for bipedal robot balance with deep reinforcement learning and pattern generators

Recovering after an abrupt push is essential for bipedal robots in real-world applications within environments where humans must collaborate closely with robots. There are several balancing algorithms for bipedal robots in the literature, however most of them either rely on hard coding or power-hungry algorithms. We propose a hybrid autonomous controller that hierarchically combines two separate, efficient systems, to address this problem. The lower-level system is a reliable, high-speed, full state controller that was hardcoded on a microcontroller to be power efficient. The higher-level system is a low-speed reinforcement learning controller implemented on a low-power onboard computer. While one controller offers speed, the other provides trainability and adaptability. An efficient control is then formed without sacrificing adaptability to new dynamic environments. Additionally, as the higher-level system is trained via deep reinforcement learning, the robot could learn after deployment, which is ideal for real-world applications. The system’s performance is validated with a real robot recovering after a random push in less than 5 s, with minimal steps from its initial positions. The training was conducted using simulated data.

Analytical study on reinforced concrete frame under high temperature with loading condition at steady state analysis

Technological advancements in the development field compare to a more extensive transformation in urban lifestyle and in designing of structure. The presentation of new reinforcement materials in concrete, notably iron, steel, and other reinforcing components, has sparked interest in enhanced concrete technology. Concrete reinforcement dates back hundreds of years, and several progressions are blended to ad lib the solid's qualities through reinforcement. Based on this finding from the prior research examines, a change in reinforcement patterns is done to explore the deflection of concrete of M30 grade under elevated temperature. For the assessment, middle and corner frame are considered with the amount of steel of four numbers of 16 mm diameter for column and 8 mm diameter is utilized for the stirrup at 150 mm C/C spacing. A live load of 3.5 KN/m and a wall load of 14.7 KN/m is applied on the compression member. Using finite element software ABAQUS the analytical works are done. The steady state analysis of eight models of bare frame, infill frame with different bay openings, infill frame with different storey openings are done. The frame model is created and meshes using the C3D8T meshing type for an 8-node thermally coupled brick mesh with a mesh size of 25 mm. The simulation results are used to explore the effects of temperature with loading condition on the reinforced concrete frame, and its structural properties are provided as performance graphs in the result section. The model is simulated utilizing steady state analysis and characteristics like as deformation and failure rate under thermal load.

Presidential debates and voter decision making

ABSTRACT Research suggests that televised debates, which create a rare but valuable environment of cross-cutting exposure, result in partisan reinforcement and polarization. Extending this line of inquiry, the present study aims to provide a more nuanced understanding of debate effects by re-conceptualizing their nature and boundary. Analyses of national survey data collected in two election cycles demonstrate that debate viewing strengthens a voter’s decision-making routine whereby partisan identity informs political opinions. This pattern of partisan reinforcement by debate viewing was observed for both debated and non-debated issues, suggesting that debate effects transcend the context of any given debate. Discussion focuses on electoral and democratic implications of presidential debates.

Bending analysis of functionally graded porous nanocomposite beams based on a non-local strain gradient theory

In the present work we study the static response of functionally graded (FG) porous nanocomposite beams, with a uniform or non-uniform layer-wise distribution of the internal pores and graphene platelets (GPLs) reinforcing phase in the matrix, according to three different patterns. The finite-element approach is developed here together with a non-local strain gradient theory and a novel trigonometric two-variable shear deformation beam theory, to study the combined effects of the non-local stress and strain gradient on the FG structure. The governing equations of the problem are solved introducing a three-node beam element. A comprehensive parametric study is carried out on the bending behavior of nanocomposite beams, with a particular focus on their sensitivity to the weight fraction and distribution pattern of GPLs reinforcement, as well as to the non-local scale parameters, geometrical properties, and boundary conditions. Based on the results, it seems that the porosity distribution and GPLs pattern have a meaningful effect on the structural behavior of nanocomposite beams, where the optimal response is reached for a non-uniform and symmetric porosity distribution and GPLs dispersion pattern within the material.

Structural Response Of A Slotted Bridge Pier Under Blast Loading Using Finite Element Analysis

Bridge pier is a crucial part for the transportation in marine structures. Scouring is a major cause for the failure of the pier. slot among the other countermeasures increases the efficiency of scour reduction and minimizes the failure due to scour.as we provide the slot; the strength of the pier reduces compared to the conventional pier. change in reinforcement pattern in slotted bridge pier changes the behavior of the pier under similar loading conditions. blast occurrence has increased in recent times and rehabilitation of a structure and improvement of strength against explosion is necessary in structure. this paper studies the behavior of slotted bridge pier under blast loading and compares theoretical and analytical aspects for the same. Design criteria for blast load according to NCHRP 12-72 are followed to carry out theoretical load response of the pier under blast loading. Analytically the behavior of pier is checked using coupled eulerian lagrangian approach using ABAQUS software. a detailed eulerian domain and slotted pier with reinforcement is assembled in ABAQUS to analyze the behavior of pier under explosion using TNT of 100kg at a scaled distance of 4ft for the period of 0.02seconds. this design gave better result in terms of mitigating effects of blast on slotted bridge pier.

Analytical Solution for Sound Radiation Characteristics of Graphene Nanocomposites Plate: Effect of Porosity and Variable Edge Load

The effects of graded dispersion of graphene platelets and porosity on vibro-acoustics of nanocomposite plate exposed to variable edge loads are analytically investigated. Voigt and Halpin–Tsai micromechanics model is used to obtain effective properties of the porous graphene nanocomposites. The strain energy technique is implemented to estimate the buckling load ([Formula: see text]). By means of Reddy’s third-order shear deformation theorem and Rayleigh Integral, vibration and acoustic responses are obtained. After validating the present analysis with the published results, the nature of edge loads on buckling and vibro-acoustic response is significant. It is noted that an increase in the intensity of non-uniform in-plane loads leads to changes in free vibration modes and resonant amplitude of response. The weight percentage and grading pattern of graphene reinforcement cause the stiffness hardening effect, whereas porosity distribution and coefficients cause the stiffness softening effect on the nanocomposite plate. It is found that the plate with symmetric distribution of graphene platelets with more concentration at the surface and symmetric porosity variation with more porosity at the center radiates less sound power.

On the theory of constitutive equations for composites with different resistance in compression and tension

The paper proposes a new approach to the construction of nonlinear constitutive equations for the description of elastic deformation of fibrous composites with different resistance in compression and tension. The framework of the approach is the generalized rheological method of constructing constitutive equations of the uniaxial stress–strain state. Transition to the tensor equations uses the hypothesis of existence of a special cone of all possible compression states in the space of strains. The cone structure is governed by the reinforcement pattern of a composite. When imposed with strains in the cone, the composite behaves as a linearly elastic medium, while beyond the cone, the composite is nonlinear, with higher stiffness conditioned by tension of high-modulus reinforcement fibers. It is highly critical that the constitutive equations obtained using this approach belong to the theory of hyperelasticity. The elastic potentials of stresses and strains are obtained for these equations, which guarantees implementation of fundamental principles of equilibrium thermodynamics. Application of the developed general theory is exemplified by construction of the constitutive equations for the plane stress state of a thin unidirectional fiber reinforced composite plate and for a multilayer plate with different-direction reinforcement of layers. Using the finite element method in combination with the initial stress method, the stress and strain patterns are analyzed in rectangular one-, two- and three-layer carbon fiber reinforcement polymer plates with a circular cut under the action of external stresses at the boundary.