Corner Condition Research Articles

The Impact of Different Shear Wall Structure Position on Symmetric and Unsymmetric Tall Buildings

Abstract: The shear wall is a structural component used to withstand lateral stresses. These walls will absorb shear stresses and avoid construction site relocation and subsequently devastation. For instance, if the shear walls are not constructed, we cannot expect the structure to exhibit acceptable tensional behavior. The contribution of the remaining structural elements to the bending moment, shear force, torsion, and axial force, as well as the final design of all structural components, are also impacted by shear wall. Over the last two decades, there has been an almost exponential increase in the building of towering skyscrapers above 150 meters in height. Numerous identical buildings have been constructed across the Middle East and Asia, and many more are now being planned or constructed. Buildings taller than 300 meters provide significant engineering challenges, particularly in terms of structural and geotechnical design. Wind analysis is crucial for tall constructions. Numerous studies have explored the structural behavior of tall buildings with SSI by considering a range of criteria, including foundation type, soil conditions, lateral loads. The current study presents G+18-story rectangular building and a asymmetric building with a 3 m floor-to-floor height was evaluated in ETABS in zone III. The structure's resistance to static and dynamic wind and seismic forces has been studied using shear walls in various locations, such as without shear walls, shear walls in the outer center, and shear walls at the corners. The results obtained are compared in the form of storey drift, joint displacement and storey drift. The research indicates that the shear wall at outer Centre with firm soil has the best response compared to without shear wall and shear wall at corner condition for symmetrical building. And for asymmetrical building shear wall at corner condition has best response compared to without shear wall and shear wall at outer centre condition.

Error free physically unclonable function with programmed resistive random access memory using reliable resistance states by specific identification-generation method

A high performance physically unclonable function (PUF) implemented with WO3 resistive random access memory (ReRAM) is presented in this paper. This robust ReRAM-PUF can eliminated bit flipping problem at very high temperature (up to 250 °C) due to plentiful read margin by using initial resistance state and set resistance state. It is also promised 10 years retention at the temperature range of 210 °C. These two stable resistance states enable stable operation at automotive environments from −40 to 125 °C without need of temperature compensation circuit. The high uniqueness of PUF can be achieved by implementing a proposed identification (ID)-generation method. Optimized forming condition can move 50% of the cells to low resistance state and the remaining 50% remain at initial high resistance state. The inter- and intra-PUF evaluations with unlimited separation of hamming distance (HD) are successfully demonstrated even under the corner condition. The number of reproduction was measured to exceed 107 times with 0% bit error rate (BER) at read voltage from 0.4 to 0.7 V.

A study of the compressive behavior of concrete columns confined with SRP jackets using digital image analysis

This paper describes the results of an experimental study carried out to understand the behavior of short plain concrete prisms with a square cross-section confined by steel reinforced polymer (SRP) jackets subjected to a monotonic concentric compressive load. The effectiveness of the confinement is studied in terms of load-bearing capacity and ultimate strain with respect to unconfined prisms. Test parameters considered in this study are the density of steel fibers, concrete corner condition, concrete surface treatment, SRP jacket height, and number of confinement layers. Digital image correlation (DIC) is used to qualitatively and quantitatively study the displacement and strain fields on the composite surface. SRP confinement is shown to improve the compressive strength and the ultimate strain of concrete prisms relative to the unconfined condition. Increases in fiber density and number of confinement layers are not proportional to increases in confined compressive strength.

Tarso Design Framework – Expert Views on Standardization and Best Practices

Given the importance of a tensile membrane architecture's corner condition (termed “tarso” by this research), a series of expert interviews were conducted as the foundation for proposing a design framework to improve tarso design in the tensile membrane field. This paper presents the design, methods and process of conducting the expert interview, then provides the interviewees’ perspectives on current tarso design issues and potential solutions. This paper focuses on synthesizing these expert's views on best practices and standardization challenges for tarso. In addition, a concept of the tarso design framework is also presented. Finally, the paper concludes with the plan for evaluating the proposed tarso design framework.

Paper Currency CIS Image Fuzzy Enhancement and Boundary Detection

According to the features of paper currency CIS image, the fuzzy set theory is initial used to improve the contrast of banknote target and background, paper money’s edge pixels are obtained by scanning, and then the sub-pixel edges are fitted by least square method; in the fitting process, the error threshold method is applied for eliminating noisy edge points, then slope correction of paper money is carried out according to the angle of sub-pixel edge line and the note area is extracted, finally, fuzzy enhancement is used for the extracted image again. Experiments show that, this method has good versatility, high accuracy and strong anti-interference ability, it can even extract the paper currency area effectively in the edge deterioration and unfilled corner condition, and the enhanced image is in favor of subsequent paper currency recognition.

Experimental investigation on the aerodynamic behavior of square cylinders with rounded corners

The influence of corner shaping on the aerodynamic behavior of square cylinders is studied through wind tunnel tests. Beside the sharp-edge corner condition considered as a benchmark, two different rounded-corner radii (r/b=1/15 and 2/15) are studied. Global forces and surface pressure are simultaneously measured in the Reynolds number range between 1.7×104 and 2.3×105. The measurements are extended to angles of incidence between 0° and 45°, but the analysis and the discussion presented herein is focused on the low angle of incidence range. It is found that the critical angle of incidence, corresponding to the flow reattachment on the lateral face exposed to the flow, decreases as r/b increases and that an intermittent flow condition exists. In the case of turbulent incoming flow, two different aerodynamic regimes governed by the Reynolds number have been recognized.

Effects of free-stream turbulence and corner shape on the galloping instability of square cylinders

The influence of corner shaping and turbulence intensity on the aerodynamic stability of square cylinders is studied with a quasi-static approach. Beside the sharp-edge corner condition, two different rounded-corner radii (r/b=1/15 and 2/15) are considered. The stability analyses are based on aerodynamic coefficients derived through static wind tunnel tests in smooth and turbulent flow, in the Reynolds number range between 1.7×104 and 2.3×105. The experimental data are employed to determine the stability boundaries depending on the angle of attack and – when relevant – on the Reynolds number.

Increase of Crosstalk Noise Due to Imbalanced Threshold Voltage Between nMOS and pMOS in Subthreshold Logic Circuits

An abnormal increase in crosstalk noise in subthreshold logic circuits is observed for the first time. When the threshold voltages ( V TH) of nMOS and pMOS are imbalanced and the on-resistance of the aggressor driver is much lower than that of the victim driver, large crosstalk noise is observed, because the on-resistance has an exponential dependence on V TH in the subthreshold region being different from normal voltage operations. A simple crosstalk noise model is also proposed and verified with SPICE simulations. In a crosstalk noise test chip with a 1.5-mm interconnect in 40-nm CMOS at a power supply voltage ( V DD) of 0.3 V, the measured noise amplitude increases from 32% of V DD to 71% of V DD, when V TH imbalance is realized by tuning body bias in pMOS. This body bias tuning can be used to mitigate the crosstalk problem in chip designs. For noise induced by a rising edge, the noise becomes largest under the slow-nMOS/fast-pMOS corner condition, while for noise induced by a falling edge, the noise becomes largest under the fast-nMOS/slow-pMOS corner condition, which is explained by the proposed model.

Seismic Racking Test Evaluation of Silicone Used in a Four-Sided Structural Sealant Glazed Curtain Wall System

AbstractThis paper presents the results of a study in which four-sided structural sealant glazing (SSG) insulating glass curtain wall units were subjected to cyclic racking test methods in accordance with AAMA 501.6 testing protocols. The test configuration included three side-by-side primary units and a corner unit. High-resolution cameras were utilized to capture instantaneous images during the racking test so that the displacement within the sealant joint could be captured and isolated from the displacement of the entire glazed unit. Drift capacity of the system in terms of glass attachment and sealant performance is reported in detail for different levels of racking displacements and boundary conditions. The overall behavior of the system is characterized, and specifically the sealant performance at a corner condition during racking drift is discussed. Additionally, expected strains in the sealant were calculated using a linear-elastic finite element model and were then compared with the strains the actual structural sealant joint underwent during system testing. Silicone sealant damage was evaluated using visual observation before and after cyclic racking. The paper discusses proposed acceptable sealant stress levels for seismic design and the durability of silicone used in the SSG system as compared to dry-glazed systems based on glass performance.

The effect of imposing a corner condition on the evolution of two-dimensional crystal morphologies by surface diffusion with anisotropic surface free energies

Continuity of the chemical potential is required from the physics of the evolution of crystal morphology by surface diffusion and in equilibrium crystal shapes (ECS). With an anisotropic surface free energy, multiple ECS with corners have been reported and instability developed in computing evolution of crystal morphology. For a cornered ECS that minimizes the total surface free energy, a corner condition is needed. Hence, in addition to continuity of the chemical potential, we add the corner condition in the evolution of crystal morphology and ensure the condition is satisfied in the numerical computation of the evolving surfaces. The evolution is governed by a nonlinear 4th order time dependent partial differential equation. By enforcing the corner condition, we obtain better stability in the evolution, which leads to ECS having lower total surface free energies than those obtained previously without satisfying the corner condition. Our study shows that the corner condition plays an important role for the cases of critically and severely anisotropic surface free energies that yield surface corners and facets.

Some Insights into Jacobi's Form of Least Action Principle

Jacobi's form of least action principle is generally known as a principle of stationary action. The principle is studied, in the view of calculus of variations, for the minimality and the existence of trajectory that connects two prescribed configurations. It is found, by utilizing a finitely compact topology on the configuration space, that every pair of configurations can be connected by a minimal curve. Therefore it is a principle of minimum action if the corner condition is allowed. If the set of rest configurations (zero kinetic energy) is empty, then the minimal curve is a minimal trajectory, implying that Fermat's Principle for the geometrical optics is a minimum principle because the speed of light does not vanish. If that set is not empty, then a minimal curve may either be a minimal trajectory or consist of minimal trajectories and curves Cl lying on the surface of rest configurations. Each one of curves Cl forms a corner. A minimal trajectory satisfies the Euler–Lagrange equation and has the property that the action is minimum among all curves lying in configuration space.

Minimizing Sequences Selected via Singular Perturbations, and their Pattern Formation

We study the Cahn-Hilliard energy E ɛ(u) over the unit square under the constraint of a constant mass m with (ɛ > 0) and without ɛ= 0) interfacial energy. Minimizers of E 0(u) have no preferred pattern and we select patterns via sequences of conditionally critical points of E ɛ(u) converging to minimizers as ɛ tends to zero. Those critical points are not minimizers if the singular limit has no minimal interface. We obtain them by a global bifurcation analysis of the Euler-Lagrange equations for E ɛ(u) where the mass m is the bifurcation parameter. We make use of the symmetry of the unit square, and the elliptic maximum principle, in turn, implies that the location of maxima and minima is fixed for all solutions on global branches. This property is used to guarantee the existence of a singular limit and to verify the Weierstrass-Erdmann corner condition which proves its minimizing property.

On applications of generalized functions to beam bending problems

Using a mathematical approach, this paper seeks an efficient solution to the problem of beams bending under singular loading conditions and having various jump discontinuities. For two instances, the boundary-value problem that describes beam bending cannot be written in the space of classical functions. In the first instance, the beam is under singular loading conditions, such as point forces and moments, and in the second instance, the dependent variable(s) and its derivatives have jump discontinuities. In the most general case, we consider both instances. First, we study singular loading conditions and present a theorem by which the equivalent distributed force of a general class of singular loading conditions can be found. As a consequence of obtaining the equivalent distributed force of a distributed moment, we find a mathematical explanation for the corner condition in classical plate theory. While plate theory is not the focus of this paper, this explanation is interesting. Then beams with various jump discontinuities are considered. When beams have jump discontinuities the form of the governing differential equations changes. We find the governing differential equations in the space of generalized functions. It is shown that for Euler–Bernoulli beams with jump discontinuities the operator of the differential equation remains unchanged, only the force term changes so that delta function and its distributional derivatives appear within it. But for Timoshenko beams with jump discontinuities, in addition to changes in the force terms, the operator of one of the governing differential equations changes. We then propose a new method for solving these equations. This method which we term the auxiliary beam method, is to solve the governing differential equations not in the space of generalized functions but rather to solve them by means of solving equivalent boundary-value problems in the space of classical functions. The auxiliary beam method reduces the number of differential equations and at the same time obviates the need to solve these differential equations in the space of generalized functions which can be more difficult.

Buckling of Skew Plates and Corner Condition for Simply Supported Edges

The paper considers the elastic buckling of skew plates subjected to in‐plane loadings. The buckling analysis is performed using the Rayleigh‐Ritz method with the newly proposed pb‐2 Ritz functions, which consist of the product of a two‐dimensional polynomial function and a basic function. The basic function is formed from taking the product of the equations of the boundaries, with each equation raised to the power of 0,1, or 2 corresponding to free, simply supported, or clamped edges; thus satisfying the kinematic boundary conditions at the outset. With pb‐2 Ritz functions, the analyst avoids the difficulty of searching for the appropriate function for any arbitrarily shaped plates with various combinations of supporting‐edge conditions. Using this efficient and accurate pb‐2 Rayleigh‐Ritz method, buckling solutions are obtained and presented in the form of design charts for skew plates with different edge conditions, angles, and aspect ratios. In addition, the differing viewpoints on the kinematic condition for a corner formed by two simply supported edges are discussed.

Second-Order Absorbing Boundary Conditions for the Wave Equation: A Solution for the Corner Problem

The treatment of domains with corners in the problem of absorbing boundary conditions for the wave equation is very important from a practical point of view. A technical difficulty appears as soon as conditions of order greater than or equal to 2 are considered. A solution is proposed for the two-dimensional case when second-order conditions are used. This solution consists of prescribing an adequate corner condition. The problem thus obtained is analyzed theoretically and the condition is proved to be optimal. The results obtained here are illustrated by numerical simulations. Some extensions to higher-space dimensions and higher-order conditions are proposed.

Penalty resolution of the babuska circle paradox

If the solution for a simply-supported circular plate is approximated by a sequence of finite element solutions on successively refined polygonal domains the finite element approximations converge to the solution of a different problem. In the present study we present a finite element formulation with boundary penalty that produces valid approximations to the simply-supported plate. The penalty term is shown to require the use of reduced integration. The dependence of the penalty parameter on mesh size h is also examined. Numerical experiments confirm the validity of the method and determine rates of convergence. A second approach involving a modified corner condition is also considered and error estimates determined. This scheme is implemented also using a discrete penalty technique. The results and rates are compared with the boundary penalty method and their relative merits discussed.

Existence and non existence of capillary surfaces

A general criterion for existence of solutions of the capillary equation, introduced by Concus and Finn [1] and by Giusti [7], is shown to be equivalent to the question of existence of certain vector fields. The result is applied to particular boundary configurations, and it is shown that in some cases the local “corner condition” of [1] is both necessary and sufficient in the global configuration. In other situations a different kind of unstable dependence on the boundary geometry appears, that could not have been predicted by previous results.

Anomalous Magnetic Moment of the Charged Intermediate Vector Boson

Assuming that the intermediate vector boson for weak interactions has no strong interactions, we reinvestigate the Corben-Schwinger problem of the scattering of a charged vector meson with anomalous magnetic moment by an external static Yukawa potential, or in particular a static Coulomb field. Meixner's corner condition of finite integrated energy in every bounded region is applied in the neighborhood of the singularity of the Yukawa potential, and it is found that the Corben-Schwinger problem, although nonrenormalizable, possesses a finite, unique solution if and only if the anomalous magnetic moment is larger than unity. It is therefore a characteristic of nonrenormalizable theories that there may be lower bounds to coupling constants. Experimental determination of the anomalous magnetic moment of the intermediate vector boson is thus of great importance. Furthermore, because certain differential equations happen to be solvable in terms of Bessel functions, an explicit perturbation expansion for weak coupling can be given for this scattering process.

Coulomb Scattering of a Charged Vector Meson with an Electric Dipole Moment

We generalize, by including an electric dipole moment that leads to parity nonconservation, our previous investigation of the scattering of a charged vector meson by a static Yukawa potential, or, in particular, a static Coulomb field. The existence of a solution that satisfies Meixner's corner condition requires the following inequality between the anomalous magnetic moment $\ensuremath{\kappa}$ and the electric dipole moment $w: \ensuremath{\kappa}g1+{w}^{2}$. In the special case where the electric dipole moment is absent, this condition reduces to the one obtained previously.

Necessary conditions for the optimal control of a system with time-varying transport lags

Necessary conditions to be satisfied if the control of a system with time-varying transport lags is to be optimal, are derived. These correspond to the Euler-Lagrange equations, the first corner condition, and the transversality condition of the calculus of variations. The systems considered can be nonlinear, have a multivariable control, and contain a number of different transport lags. The states and controls of the system are assumed to be unbounded.