Simple Design Method Research Articles

Hysteretic behavior of replaceable low yield point steel links with corrugated web

To develop a new replaceable steel link with high energy dissipation capacity for establishing a rapid recoverable system of bridge piers, a novel demountable and replaceable low yield point steel links with corrugated web (LCSW link) is proposed. A series quasi-static test on six specimens was conducted to investigate their failure process and hysteretic behaviors, considering the effects of different material and shape of the webs, as well the height-to-span ratio of the replaceable link. The experimental results indicate that the LCSW links exhibit three types of failure modes: the local buckling of steel flanges, the welding fracture at flange-to-endplate connection, and the combination of welding fracture at flange-to-endplate connection and shear buckling of CSWs. The hysteretic behaviors of the specimens were mainly affected by the height-to-span ratio. Moreover, utilization of a small height-to-span ratio (1.7 in this paper) and low yield point steel (LYP160 steel) in the links improves the ductility and energy dissipation capacity. Three-dimensional nonlinear finite element models were established to simulate the hysteretic behavior of the LCSW links, and the yield strength and initial stiffness of the LCSW links under lateral loading were obtained through finite element simulation and simplified design method. The comparison of experimental and analytical results indicates that the finite element models were able to simulate the cyclic response well, and these proposed theoretical equations can be used efficiently to predict the capacity of LCSW links.

Simplified Method for the Preliminary Design of Shear-Controlling Rocking-Isolation Podium Systems for Tall Buildings

Simplified Method for the Preliminary Design of Shear-Controlling Rocking-Isolation Podium Systems for Tall Buildings

Study of the Mechanical Properties of Beam-Column Joints in a New Type of Aluminum Alloy Portal Frame

In the article, the semi-permanent aluminum alloy portal frame is used as the research background, beam-column joints are used as the research object, and experimental and numerical analyses are carried out. The influence of different bolt diameters and arch angles on the mechanical properties of beam-column joints under vertical load was analyzed using five sets of experiments. The experimental results show that the load–displacement curves of different bolt diameters in the elastic stage are basically consistent. After entering the plastic stage, the ultimate load first increases and then decreases, and the ultimate displacement is basically consistent. According to the experiment, there is no significant difference in the load–displacement curve when the arch angle increases from 90 degrees to 108 degrees. When the arch angle increases to 126 degrees, the stiffness and ultimate bearing capacity of the node under vertical load significantly increase. Then, a numerical analysis model was established to analyze the mechanical performance of beam-column joints under horizontal loads. The numerical analysis results indicate that under horizontal load, as the diameter of the bolt increases, the yield load, yield displacement, ultimate load, and ultimate displacement of the beam-column node exhibit no significant changes, and the change amplitude is minimal. When the beam-column node is subjected to horizontal loads, as the arch angle increases, the yield and ultimate displacement increase by 2.14 times and 2.78 times, respectively, and the yield and ultimate load decrease by 58% and 48%, respectively. Finally, a simplified design method for beam-column joints was proposed based on experiments and numerical analysis.

Implementasi Pelayanan Samsat Tanjak dalam Meningkatkan Pelayanan Pajak Kepada Masyarakat Perawang

This study was conducted to discuss the implementation of SAMSAT TANJAK services to the people of Tualang sub-district, Siak district. This research was structured using a quasi-qualitative or quasi-qualitative type of research. The method that the author uses in this research is the simple research design (SRD) method. Theresults of this research are the implementation of Samsat Tanjak services in improvingtax services to the Perawang community. The findings in this research show that fromthe aspect of information system support, company location, atmosphere of the serviceplace/ decoration and layout have not run optimally, while from the management aspect, customer handling and company equipment have run well.

Modelling and lock-seam effects on compressive behaviour of concrete-filled helical corrugated steel tubes

Concrete-filled galvanized helical corrugated steel tube, abbreviated as CFCST, is a new type of composite member that has great potential to be used in seismically active regions or highly corrosive environments. However, the unique lock-seam connections of helical corrugated steel tube (CST) result in high difficulty in precise simulation analysis, and the effects of such connections on the mechanical properties are not clear, so further investigations are needed. This paper attempts to present a detailed finite element (FE) model of CFCST with the real dimension of lock-seam connections, and then investigate the effects of lock-seam connections on the basic compressive behaviour of CFCST stub columns. The FE models are developed with the consideration of the real shape of helical CST, the non-linearity of each constituent material, and the interfacial properties at lock-seam regions. The simulated results are verified carefully through comparisons against experimental results of 41 stub columns under axial compression in terms of failure modes, load–displacement histories, and local stress developments. The influence of lock-seams on the working mechanisms has been particularly investigated and discussed. Parametric studies have also been conducted to investigate the compressive behaviour of the CFCST. Finally, simplified design methods for axial compressive bearing capacity are proposed.

A Simplified Design Method for Quasi-Resonant Inverter Used in Induction Hob

Induction heating (IH) technology is widely recognized and utilized in residential applications due to its high efficiency and safe operating characteristics. Resonant inverter circuits are widely used in IH systems because of their high efficiency and ability to perform soft switching. Among the various resonant inverters used in IH systems, the single-switch quasi-resonant (SSQR) inverter topology is typically preferred for low-cost and low-output-power applications. Despite its cost advantage, the SSQR topology has a relatively narrow soft-switching range, which can be unstable depending on the electrical parameters of the load and the resonant converter circuit. Accurately determining the capacitance value of the resonant capacitor and the inductance value of the induction coil, which are the key circuit elements of the SSQR induction cooker, is crucial for designing a reliable, efficient, and durable cooking system. In other words, there exists a critical relationship between the resonant converter circuit parameters, load characteristics, and safe operating conditions. Additionally, when considering closed-loop control methods used for power control and safety, selecting appropriate resonant circuit elements becomes vital in ensuring both reliable and efficient operation. This paper focuses on a novel and simplified design method for the SSQR inverter utilized in household appliances. The proposed method and its advantages in terms of the safe operating area of the switch are theoretically investigated and verified through simulations and prototype circuits.

Influence of pile-raft connection on lateral performance of combined pile-raft foundations adjacent to tunnelling

The lateral response of combined pile-raft foundations (CPRFs) adjacent to tunnel excavation is a challenging problem owing to the complexity of the pile-raft connections. In current engineering practices, the impact of these connections on the lateral performance of CPRFs is frequently overlooked, despite their importance. To address this issue, this study conducted three-dimensional finite element analyses to evaluate the contribution of pile-raft connections to the tunnelling-induced lateral performance of CPRFs in saturated clay. In the analysis, both passive and active loading at the pile head could be considered by varying the tunnel depth. Several parameter studies, such as relative pile-raft modulus, pile embedded modulus, pile embedded depths, and pile shaft skin friction, were conducted to determine the optimal design parameters for CPRFs. The results indicate that pile-raft connections significantly affect the tunnelling-induced deflections and bending moments of pile groups. Inspired by the results, a simplified design method, the pile-raft connection coefficient Kc was proposed. Additionally, the pile-head restraint percentage was established to make a relationship with the pile-raft connection coefficient in order to assess the pile-raft connection and guide the pile-raft design. In this paper, the recommended range value of Kc is 10–200 and the range value of pile-head restraint percentage is 24%–42%.

The tyre blow-out vehicle lateral pulling control using an active suspension system with comfort-lateral trajectory based control scheme.

When a tyre blows out, the vehicle’s trajectory deviates from the intended path, resulting in an accident and death. Because of its larger contact patch, applying more steering force to the flat tyre will cause the tyre to separate from the wheel. Also, improper braking effort causes rollover related issues due to the sudden vehicle’s centre of gravity (C.G.) displacement and weight transfer towards the blow-out tyre. Therefore, this research attempts to return the C.G. to its initial position through the suspension control. The force supplied between the sprung and unsprung masses of the flat tyre through suspension actuator is estimated and controlled by the model predictive control (MPC) scheme with respect to its input signals. For the non-linear simulation, the four-wheel passenger car vehicle dynamic model and the combined empirical model for the tyre inflation pressure effect are used. And the equivalent plant model is identified through a simple system identification method for the MPC design. The passive and active based suspension of standalone, roll-resistant interconnected and pitch-resistant interconnected systems, including the proposed comfort-lateral trajectory controlled standalone active suspension, were examined. To assess the effectiveness of each suspension and its control strategy in a tyre blow-out scenario, a vehicle was analysed with various longitudinal velocities along with and without steer input.

Analytical Model for the Design of Permeable Reactive Barriers Considering Solute Transport in a Dual-Domain System

A permeable reactive barrier (PRB) is an effective groundwater in situ remediation technology, and the design methods used for PRBs are significant in ensuring that they meet remediation goals. Steady-state analytical solutions are an effective tool to provide conservative and simple design methods. A steady-state analytical solution is proposed to describe organic contaminant transport through the PRB and aquifer in a PRB and cut-off wall system. The proposed analytical solution may serve as an effective tool to provide conservative and simple design methods. The shape factor (S) is introduced at the PRB-aquifer interface to investigate the effects of a PRB’s layout forms on its performance. The results show that the relative contaminant concentration at the point of compliance for a PRB with S=8 is 11 orders of magnitude larger than that without considering the shape factor. Effects of degradation, dispersion, and advection on PRB design are subjected to dimensionless analysis. Dimensionless analysis shows that degradation plays a key role in decreasing contaminant concentration in the PRB. In addition, increasing advection may promote contaminant transport from the source to the aquifer. Simplified solutions to estimate PRB thickness and source remediation time are derived for the practical design and performance evaluation of the PRB system.

Influence of Imperfections in the Design of Crane Runway I‐Beams

AbstractCrane runway beams are generally loaded by vertical and horizontal forces as well as not‐negligible torsional actions. Horizontal and torsional deformations originate already from the 1st order analysis. The effects of imperfections of crane runway beams could, at least partially, be simulated by these deformations. While for the purely vertically loaded beams it is necessary to consider the horizontal bow imperfection, for the generally loaded beams with horizontal forces as well, the influence of horizontal bow imperfection may not be as important, due to the occurrence of horizontal deflection from primary actions. Eurocode EN 1993‐6 allows to consider either eccentricities of vertical forces or introduction of horizontal bow imperfections in the design of crane runway beams. In this article, using a self‐developed FEM‐program, the effect of horizontal bow imperfection for the generally loaded crane runway beams is investigated. The two options of EN 1993‐6 are compared in the FEM analyses with the simplified design methods like the Annex A method of the same standard and the Naumes method.

Orthotropic metamaterials with freely tailorable elastic constants

To control mechanical waves and structural vibrations, an important method is to design metamaterials with tailored elastic constants, but it is very difficult. In this paper, a simple and universal metamaterial design method is proposed. This orthotropic metamaterial is composed of elements arrayed periodically in space. The element includes two cuboid structures. The first structure is the basic structure of the element, and the second structure is the transformation of the first structure of the element. The first structure of the element is a cuboid structure composed of 24 bars connected by 8 nodes, and the second structure of the element is a cuboid structure composed of 36 bars connected by 14 nodes. This metamaterial has six independent elastic constants, so there is a large degree of freedom in the material design. Therefore, it has great application value in the fields of mechanical metamaterials, elastic wave metamaterials, acoustic metamaterials, and seismic metamaterials, and has also laid the foundation for realizing the dream of controlling mechanical waves and structural vibrations.

Review and outlook about the use of high strength steel in encased composite columns

AbstractThe trends of the modern construction are recognized for many years; go large span, go light structures, go sustainable, and keep it simple. In the holistic approach to construction a column remains one of the key structural elements.This article presents benefits of the application of high strength steel; namely the potential of using S500 and S550 for encased composite columns. The study shows the increase of the buckling capacity and reduction of weight and consequently reduction of the carbon footprint especially when applying XCarb® steel. The results are presented for a single member as well as for an internal column of a 156m high office building.It is assumed in the analyses that the simplified design method for composite columns defined in EN1994‐1‐1:2004 is applicable to higher steel grades and higher concrete compression classes. Different typologies of the encased steel cross sections are considered: simple H section in rectangular encasement, and cruciform section.

Development of a Simple Design Method for an Infiltration Facility using Curve Number

As climate change accelerates, the scale and intensity of natural disasters are increasing, and the frequency of localized heavy rains is increasing rapidly. Urban watersheds have a high ratio of impervious areas. So there is a high possibility of flooding in the event of torrential rain, and large-scale damage can occur because the population and material resources are highly concentrated. River improvements, sewerage maintenance, and rainwater storage installations are frequently used to reduce flood damage. More recently, low-impact development (LID) techniques have been proposed; however, LID facilities are installed on a small scale and in various locations. In addition, they require many parameters for a rainfall-runoff analysis; consequently, the design of these facilities require too much manpower and time. In this study, we analyze the rainfall-runoff reduction effect based on the size of a facility to present a simpler, more efficient design method. Next, the curve number (CN) corresponding to the capacity of each facility is estimated and the correlation between the facility’s area ratio and the CN is analyzed. As a result, a relational expression that can calculate the new CN with the same rainfall-runoff reduction effect as the installed LID facility was derived by using the CN before the installation of the LID facility and the facility area ratio. Thus, we present a simple design method using the recalculated CN without directly entering LID facilities into a storm water management model (SWMM).

Design approach and its optimization for bolted steel plate strengthened RC beams considering the effect of connection bolt slip

The use of bolted steel plates (BSP) has been found to be an effective method for increasing the flexural capacity of reinforced concrete (RC) beams. However, slip in bolt connections is an inevitable occurrence that affects the mechanical behavior of the BSP beam. While prior studies have thoroughly examined the effects of bolt connection slip on the flexural capacity of BSP beams, assuming unlimited slip, experimental results revealed that bolt connection failure takes place when slip surpasses a specific threshold. The current design methodology does not accommodate this finding. To address this issue, a simplified design method for practical applications is proposed. Comprehensive parameter studies were conducted on the enhanced moment capacity ratio and maximum bolt slip, involving a total of 13,824 and 276,480 calculations, respectively. It is found that several parameters (e.g., the aspect ratio of RC beam, the tensile longitudinal reinforcement ratio, the height of steel plate) affect the two above-mentioned indexes. Equations were then developed to determine the enhanced moment capacity ratio and maximum slip. It is noteworthy that the recommended effective yield slip (0.55 mm) is obtained based on adhesive anchor, which should be checked when other types of anchors would be used. Relying on these equations, an optimized design approach for BSP beams is introduced that avoids complex iterative processes. The effectiveness of the optimized design methodology is substantiated through a practical example.

Theoretical modeling for predicting the shear strength of partially-encased composite members with multiple transverse stiffeners

Partially encased composite (PEC) members are frequently used as girders in heavily-loaded or long-span structures. In PEC members, the steel web is encased in web concrete between the top and bottom flanges. When PEC members are used in continuous beam spans, the intermediate support area is subjected to significant shear force and negative bending, which is more critical than the span center. As a result, accurate prediction of shear strength is crucial for structural safety in practical design. Unlike traditional concrete or steel beams, PEC beams have multiple shear transfer mechanisms consisting of concrete, steel flanges, axial steel web, and transverse stiffeners (if necessary), and it is essential to investigate the shear contributions of the different mechanisms and how they work together as a composite structure. To solve this problem, this paper presents a novel shear strength model, in which the global shear strength is composed of two main components: the composite truss (steel flanges, web concrete, and transverse stiffeners) and the axial steel web, and these two components are unified by strain compatibility to show the composite action. Then, the proposed model is compared with existing shear equations using 25 existing specimens in the literature, and the results indicate that the proposed model can predict the shear strength of PEC beams with sufficient accuracy. Finally, the paper presents a simplified design method after validating the shear contributions of different anti-shear mechanisms, and the simplified method can facilitate practical design in engineering practices.

SIMPLIFIED MODELING OF V-SHAPED BRIDGE PIERS

DDesigning a steel, V-shaped bridge pillar requires a complex and detailed finite element calculation model. The calculation can be simplified by using a simple one-dimensional beam model, but then the stress concentrations are not determined in detail. The use of a stress concentration factor, SCF, to make this possible. Before using this method, it is first verified whether both models behave correspondingly, by calculating the internal forces certain sections. Five basic load cases are used to perform this verification. Afterwards the stress concentration factors are determined for those same load cases. This method induces inconsistencies, some predictable but others unpredictable. The conclusion can however be that this simplified meth gives unreliable results. Therefore, a second method is used, where the high stresses in the curvatures of the pillar are related to the stresses in a nearby neutral section. Such a neutral section is defined as a section where the stress peaks due to the geometric effects caused by the actual geometry of the nodes of the V-shaped pilar are not present anymore. This method provides better results for the SCF; however, some issues remain, which are discuss in more detail in the paper. Finally, the impact of a varying radius of curvature on the stresses is also studied. Some clear trends are observed in this paper Overall, this paper discusses a possible simplified design method for V-shaped bridge pillars, at the same time listing the relevant design difficulties and possible pitfalls of a too simplified model.

Return on Equity, Cash Ratio & Debt Equity Ratio Affect Stock Returns in the Banking Industry Listed on the IDX With Non-Performing Loans as a Moderating Variable

This study aims to determine the effect of return on equity, cash ratio and debt to equity ratio on stock returns in the banking industry listed on the IDX with non-performing loans as a moderating variable. The research design used is the simple design method. The population used in this study are banking companies listed on the Indonesia stock exchange for the 2016-2021 period, with a total sample of 26 companies using 156 data samples. The data analysis technique used is panel data analysis using the e-views program. The results of the study show that Return on equity has a positive and insignificant effect on stock returns, Cash ratio has a negative and significant effect on stock returns, Debt to equity ratio has a positive and insignificant effect on Return, Non-performing loans cannot moderate the effect of return on equity on returns stocks, non-performing loans cannot moderate the effect of cash ratio on stock returns and non-performing loans cannot moderate the effect of debt to equity ratio on stock returns. Keywords: Return on Equity, Cash Ratio and Debt to Equity Ratio, Stock Return, Non-Performing Loan

New Swiss technical specification SIA 2057 for glass structures and its post failure limit state concept

Until recently, designing and constructing with glass in Switzerland was not performed on a uniformly regulated basis due to the lack of a national standard for glass. Therefore, foreign regulations and codes were typically applied. However, this practice repeatedly caused problems. In August 2021, the Technical Specification SIA 2057 Glass Structures has been published to close this codification gap and to create a uniform design basis for the Swiss glass industry. A wide range of glass applications is covered, taking into account the latest findings from practice and science, such as use of shear transfer in laminated glass. The SIA 2057 follows the well-proven SIA principles of regulating only where necessary. Thus, a flexible application of the code is made possible, and innovation is encouraged. In addition to simple design methods, engineers are free to pursue alternative and innovative paths in glass design. The present article provides an overview of the SIA 2057 with focus on laminated safety glass design and post fracture limit state verification.

Capacity Spectrum-Based Retrofitting Method and Quick Design for Viscously Damped Structures by Utilizing the Concept of Uniform Damping Ratio

Viscous dampers have proven to be effective in enhancing the seismic performance of existing structures. Despite this, there is still a need for rapid and simplified design methods and formulae for viscous dampers that can take into account the elastic–plastic performance of structures. This study introduces a retrofit design method for existing structures using viscous dampers, based on the concept of uniform damping ratio (UDR), with the aim of fully utilizing each damper. The UDR concept assumes that each damper in the structure provides the same UDR when subjected to seismic excitations of identical intensity. In this method, the first step involves defining the equivalent damping ratio (EDR) of the damper. Then, based on the capacity spectrum of the structure, the response mitigation ratio can be determined, which helps to determine the additional EDR required from the dampers. Once the UDR and additional EDR from the viscous damper have been determined, the parameters of the dampers at each story can be rapidly obtained. To demonstrate the effectiveness of this method, a six-story reinforced concrete frame was utilized as a benchmark structure. A comparison between this UDR-based approach and a traditional design approach was also conducted. The study findings reveal that the UDR concept enables the maximum utilization of energy dissipation capacity of viscous dampers installed in the structure, leading to a more effective and economical design approach.

A simple Monte Carlo simulation method for geotechnical reliability-based design

ABSTRACT This paper proposes a simple reliability-based design approach from a quantile value perspective. The proposed approach allows the design variable to be efficiently determined without implementing repetitive “trial and error” procedures for a given target reliability index. Only a single run of Monte Carlo simulation is needed to calculate the threshold values of the design variable after the design variable function (DVF) is derived from the limit state function. The threshold values are then sorted in ascending order, and a quantile value is chosen as the desired design variable such that MCS samples with threshold values larger, or smaller than this value are undesired samples. Three illustrative examples are presented following the development of the proposed method and its implementation procedure. Results are validated by calculating the failure probabilities of desired designs using direct MCS, and they are also favorably comparable with those reported in literature. This method can play a complementary role to existing RBD methods due to its advantages of simplicity, efficiency, and robustness.