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The provisions for out-of-plane stability of steel arch bridges in three major design codes are presented in this paper. By employing an existing steel arch bridge as a model, the influence of bridge type, arch rib to lateral bracing stiffness ratio, rise-to-span ratio, arch rib spacing, and range of lateral bracing arrangements on the out-of-plane critical axial force of the arch rib is studied using FE analysis. The accuracy of the critical axial force provisions is then evaluated against the FE analysis. The results show that the influence of the rise-to-span ratio on critical axial force is generally small. The critical axial force decreases with increasing arch rib spacing when the stiffness ratio is relatively large. A smaller ratio of arch rib length provided with lateral bracing (γ-value) significantly reduces the critical axial force and normalized critical axial force decreases with increasing stiffness ratio. The critical axial force of half-through type arch bridges is lowest when the stiffness ratio is relatively small. A deck-type bridge has a larger critical axial force than a through-type bridge when the stiffness ratio is relatively large, while the results are the opposite when the ratio is small. The different assumptions made in the provisions result in the various parameters having different impacts on the out-of-plane critical axial force in each code, thus affecting code accuracy. Considering the influence of the rise-to-span ratio, ratio of lateral bracing, and arch rib spacing with different stiffness ratios, factors to improve the accuracy of the critical axial force obtained by the three codes are proposed for a practical design process.

The article deals with bridge-type buildings over small rivers of cities as an urban planning tool that facilitates transport problems in these cities. A large number of small rivers in cities, which create insurmountable obstacles for vehicles, separate urban districts preventing vehicles from moving from one district to another taking the shortest route. This circumstance forces vehicles to travel on major highways, overloading them and creating essential congestions. Embankments along small rivers also lead traffic flows to the main highways. As a result of the conducted research, the authors propose to create bridge-type buildings with transport turnpikes through these obstacles, using them for the infrastructure necessary for the city. Such bridge-type buildings can be constructed at the level of embankments, avoiding access trestles that significantly clutter up the adjacent streets and require reconstruction of the surrounding territories. Small bridge-type buildings for these purposes with a span of up to 25 m based on steel-reinforced concrete structures are not expensive and can be financed by investors in case of their interest to rent premises located on the floors of such bridge-type buildings.

Due to its many advantages such as the improved power quality, high energy efficiency and controllability, etc. the variable speed wind turbine using a doubly fed induction generator (DFIG) is becoming a popular concept and thus the modeling of the DFIG based wind turbine and improvement in the transient fault conditions is an important consideration. In this paper, Transient stability improvement has been done by using Superfluous Fault Current Limiter [SFCL]. A new design of SFCL IGBT- Bridge-type SFCL shunted with a variable resistor Rsh has been proposed. Rsh is modeled to decrease the terminal voltage deviation to minimum level by reducing the amount of current at the bus terminal. Comparison of Voltage deviation and current deviation with the resistive type SFCL and IGBT- bridge-type SFCL show considerable decrease in both quantities by using IGBT- bridge-type SFCL. The values of voltage deviation at the bus terminal is 8.223 e-8 % for proposed SFCL which is less than the resistive type SFCL that is, 14.4 e-8 %. The huge voltage sag has been considerably reduced by reduction of high level of current to 0.0004401 % in IGBT-bridge-Type SFCL from 0.0004624% in resistive type SFCL. Thus proposed SFCL has caused significant improvement in transient stability keeping the deviation in active and reactive power during faults to minimum level.

Wind power generation is observing a significant use of doubly-fed induction generator (DFIG) due to its improved efficiency, but the converter used in the configuration is sensitive to the presenc...

In planning and designing a bridge it should consider the function of transportation needs, technical and architectural-aesthetic requirements which include: Traffic aspects, Technical aspects, Aesthetic aspects. the alternative bridge design structure of the steel arch bridge-type steel frame with warren frame on the Tukad Bridge in Bangkung district. Badung - Bali is a steel frame bridge that has an overall span of 360 m and 9.6 m wide. alternative upper structure at the Tukad Bangkung bridge Badung Regency - Bali with the merging of the steel arch construction of 2 roller joints and the warren frame structure. Where between the curve/arc with a steel profile plate connected by a cable that serves to provide strong support to the frame structure because of the long stretch. In the planning of the bridge this time using the L.R.F.D method and for the structural analysis modeling the writer uses the STAADPRO V8i assistive program. From the analysis of the results of the calculation of the structure above obtained planning dimensions of the Steel Arch bridge that is planned to use a steel profile, WF 350 x 175 x 7 x 11 for gel. elongated, WF 918 x 303 x 19 x 37 for gel. transversely, WF 350 x 350 x 12 x 9 for gel. transversely above, WF 498 x 432 x 45 x 70 for gel. parent, LD 250,250.25 for wind bonds.

DFIG-based wind turbine has significantly reduced the power rating, cost of the converter and enables subsynchronous and super synchronous operation but it has largely suffered in maintaining the t...

In this paper, an analytical model of elliptical bridge-type compliant mechanism is established. Compared with the traditional bridge mechanism, the elliptical bridge-type compliant mechanism has the advantages of light weight, high natural frequency, and more uniform stress distribution. Based on the strain energy and Castigliano’s displacement theorem, a static model for calculating the displacement amplification ratio and input stiffness is established. Then, the Lagrange equation is used to establish the dynamic model to calculate the natural frequency. After that, finite element simulation and experimental test are both used to verify the proposed analytical model. The results show that the maximum error between the analytical model and finite element simulation is within 8.25% and that of the experimental results is within 6.25%. The conclusion of this paper provides an accurate prediction analytical method for the mechanical performance index design of the elliptical compliant mechanism, which has important theoretical significance.

Bridges of rigid girder and flexible arch have been widely used in the construction of high-speed railways in the last several decades. This bridge type is adopted for Rongjiang Bridge in Xiamen–Sh...

Air mixing in an air mixing chamber affects an air-conditioning system's performances. Low air mixing effectiveness is associated with several problems. In this study, modified statistical air mixing effectiveness is proposed. An experimental study and CFD (Computational fluid dynamics) simulation were conducted for the development of high performance static air mixer over a short mixing distance. Based on the analysis results for the conventional air mixing chamber and the bridge type air mixer, it was determined that development strategies can be set as openings for an outdoor air discharge were placed between the openings for a return air discharge. This extends the mixing distance of an outdoor air and a return air as long as possible. Several applications to the strategies have been examined. According to the results, a “Double inducing chamber/three slits on each side wall” showed the best air mixing performance among the cases examined. Air mixing effectiveness was 87% for 30% outdoor air, and pressure loss approximately 19 Pa. The performances were validated in the experiment. The best case scenario results showed a very short air mixing distance. Air mixing effectiveness reached a high level with an air mixing distance of 0.2, and an air mixing effectiveness of 71–87% as a percent outdoor air varies from 10% to 90%.

The paper presents a full theoretical analysis of thyristors-bridge-type superconducting fault current limiter (SFCL) operational modes, supported by MATLAB/SIMULINK-based simulations. Both normal and fault current operation conditions of a SFCL-based power system under continuous conduction mode (CCM) and discontinuous conduction mode (DCM) are treated. The developed equations are shown to be valid for all possible thyristor-firing angles. Derived analytical relations are useful for both comprehensive design of thyristors-bridge-type SFCLs and analysis of circuit simulator based outcomes.

The traditional V-Y advancement flap for fingertip reconstruction has limitations such as the flap flexibility and distance for advancement. The aim of this study was to design a modified flap to obtain a greater advancement and to provide a far superior cosmetic result. From October 2016 to November 2017, 21 patients underwent the modified flap for fingertip defects reconstruction. A bipedicled bridge type combined with V-Y advancement flap was designed to obtain a greater advancement. We also improved the way of nail groove reconstruction and nail bed lengthening. All the patients were followed up for a minimum of 6 months. All flaps healed with satisfactory pulp and nail contour. All patients were satisfied with the cosmetic appearance and no complications were encountered. The distance of flap advancement can reach to more than 1 cm and flap size can also be larger than 1 cm2. The modified bipedicled bridge–type V-Y advancement flap has simple and acceptable modifications for fingertip reconstruction.

This paper presents an improved modeling method for bridge-type mechanism by taking the input displacement loss into consideration, and establishes an amplification ratio model of bridge-type mechanism according to compliance matrix method and elastic beam theory. Moreover, the amplification ratio of the designed bridge-type nano-positioner is obtained by taking the guiding mechanism as the external load of bridge-type mechanism. Comparing with existing methods, the proposed model is more accurate, which is further verified by finite element analysis(FEA) and experimental test. The consistency of the results obtained from theoretical model, FEA and experimental testing indicates that the proposed model can accurately predict the amplification characteristics of nano-positioners, which helps the analysis and design of bridge-type nano-positioners in practical applications.

Glued-laminated (glulam) and cross-laminated timbers are gaining interests in bridge engineering community due to their improved strength and enhanced durability compared to sawn lumber. The main bridge type on South Dakota local roads is a precast prestressed double-tee girder bridge, which has only one supplier in the state. In an attempt to provide more bridge type selection options for local governments, the system performance of two types of glulam timber bridges was investigated through full-scale experiments. One glulam girder bridge and one glulam slab bridge were tested under fatigue and strength loading. Both bridge types showed minimal damage during the fatigue testing and the bridge stiffness remained constant. Strength testing of the two bridge systems confirmed that the AASHTO method of design for timber bridges is adequate. Girders of glulam girder bridges should be designed as fully non-composite members. A cost analysis showed that the superstructure cost of glulam timber bridges can be 30–50% lower than the precast prestressed double-tee bridge superstructure cost. Based on the construction, testing, and cost analysis, it is concluded that both types of glulam timber bridges are viable alternatives to precast prestressed double-tee bridges to be used on local roads.

All our actions claim now sustainable choices, and radical changes in mate- rials need to be made. In this perspective there is the awareness that nature can help to provide viable solutions. In particular, the choice of natural mate- rials for structures, perfectly optimized by the structural point of view, can be made. In this paper an experimental teaching experience regarding the structural behaviour of Arundo Donax reed, made in a Structural course of Design of the Industrial Product of the University of Bologna, is reported. Arundo Donax has been firstly characterized from the mechanical point of view and then used in a structural challenge focusing on the best use of a given quanti- ty of reed for a “bridge type structure” with fixed span and width. The main goals of the course were, on one hand (with mechanical characterization of Arundo), to give students sensitiveness on strength and stiffness of the material, on the other (with the structural challenge) were to make the student think about the combination of material properties and shape of constructions to reach the best structural performances.

The more the magnitude of the earthquake, the more is the damage. During an earthquake, the mobility of the soft soil gets augmented and because most of the bridges are built on soft soil, there are even more chances of the bridge behaving like a ship in the sea. The stability of the bridges is the most crucial task to avoid all disasters. Many bridges collapse during earthquake because their mobility, and sustainability cannot stand the magnitude of the earthquake. In this paper, we have proposed a method to predict whether a bridge will sustain damage or not after an earthquake by using factors like magnitude of the earthquake, distance to epicenter of the bridge, bridge type, material used to make bridge and many more, using many classification algorithms like Logistic Regression, Decision Tree, Random Forest, XGBoost, and KNN. This prediction in turn will help to improve bridge sustainability during an earthquake, which in turn will help in saving many lives.

Objective: A study was conducted to explore the clinical efficacy and radioactive results of the bridge-type ROI-C interbody fusion cage (ROI-C) and anterior cervical discectomy and fusion with plating and cage system (ACDF) for cervical spondylopathy.Methods: From January 2014 to January 2018, 45 patients who underwent operations were retrospectively analyzed, including 24 cases of ROI-C (group A) and 21 cases of ACDF (group B). The operation time, blood loss, Neck Disability Index (NDI), Japanese Orthopaedic Association score (JOA), postoperative complications, imaging results including cervical Cobb angle, and fusion were compared between groups.Results: All patients were successfully treated with surgery. No cerebrospinal fluid leakage, esophageal fistula, or hoarseness occurred after the surgery. The operation time and blood loss in group A were lower than those in group B (P0.05). In group A, the incidence of postoperative dysphagia was 12.5%, which returned to normal after 1 month. In group B, the incidence of postoperative dysphagia was 38.1%, which was 19% after 1 month and 4.8% at the final follow-up. In group A, the fusion rate was 83.3% at 3 months after surgery and 100% at the last follow-up. The rate of adjacent level ossification development was 12.5%. In group B, the fusion rate was 85.7% at 3 months after surgery and 100% at the last follow-up. The rate of adjacent level ossification development was 23.8%.Conclusion: Both ROI-C and ACDF achieved satisfactory results, but ROI-C had a shorter operation time, less bleeding, and lower incidence of dysphagia in the short term.

This paper focused on the practical design of an isolated transformer for bridge-type PFC converter. The main issue is the high current change rate (di/dt) through the transformer caused by low leakage inductance. Thus, proximity effect loss is considered as the main power dissipation source. This work shows transformer design flow and experimental verification of the proposed configuration. Power dissipation for two types of Litz wire was compared under the same conditions.

Performance and analysis of the bridge and bridgeless type of power factor improvement method of boost converter has been presented in this paper. Conventional type of converter has higher switching and conduction losses, low power factor, high THD, and less efficiency. A bridgeless Boost converter with PFC improves power quality and has higher efficiency than other traditional, bridge boost PFC converter. Passive filters used in a bridgeless PFC boost rectifier help in reducing THD and increasing a Power factor at the source. Complete analysis of Boost full-bridge converter is done in this paper. Bridgeless type of PFC boost converter has low line current flows from source to load, one semiconductor device, improving efficiency and reduces losses in comparison to the conventional bridge type of boost converter. MATLAB simulation result has been presented which indicate that Power Factor is nearer to unity.

The compliant mechanism flexure hinge has been frequently utilized in precision enginering in recent years, such as the bridge-type and rhombus-type compliant mechanisms. While previous studies used the approximation mathamatic model to estimate the displacement amplification ratio, the results of such investigations obtained a displacement amplification ratio of approximately 30, thus, it is difficult to identify and obtain the maximum precision value. Therefore, this paper designed a new model for bridge-type compliant flexure in SOLIDWORK. The displacment amplification ratio was calculated using the finite element method in ANSYS, and the simualtion results reveal that the displacement amplification obtained 64.8 and the maximum value of stress of 101.5 MPa. Moreover, S/N analysis pointed out the factors that effect output displacement; first is the thickness of the flexure hinge, second is the length of the input body, third is the incline angle between two flexure hinges, and fourth is the fillet radius. The factors first effect on stress is the input body length, second is the thickness of the flexure hinge, third is the fillet radius of the flexure hinge, and finally, the incline angle between two flexure hinges. The ANOVA results identified the contribution of factors on the output displacement and stress. The R-sq of 99.86%, R-sq(adj) of 99.83%, and R-sq(pred) of 99.80% is output displacement. The R-sq of 99.93%, R-sq(adj) of 99.90%, and R-sq(pred) of 99.85% is output stress. The R-sq of 99.75%, R-sq(adj) of 99.67%, and R-sq(pred) of 99.57% for GRG. Regression analysis obtained the optimal output displacement of 0.6326 mm, stress of 43.398 MPa, and the optimal displacement amplification ratio of 63.26.

In this paper, we develop an accurate kinetostatic modeling method for bridge-type amplifiers by incorporating the impacts of nonlinear shear effect, center-shifting and load-stiffening. To account for the nonlinear stress-stiffening and shear effects, a Timoshenko Beam Constraint Model (TBCM) is first investigated to accurately predict the deformations of the short beam flexure hinges popularly employed in the bridge-type amplifiers. Accordingly, a flexible branched chain model is established for bridge-type amplifiers, where the input and output displacements, as well as the displacement amplification ratio and the input stiffness, are derived. The results indicate significant nonlinearities of the amplification ratio and the input stiffness with respect to the driving forces, which are further verified by the finite element analysis (FEA) results. The proposed modeling method can derive a more accurate model of the bridgetype amplification mechanism to capture its kinetostatic behaviors, which can better support the design and control of flexure mechanism based nano-manipulating systems.

For stable and flexible manipulation, realizing parallel grasping and large output stroke simultaneously has become a key issue in the researches on micro-grasping system. The typical solution is to use compliant orthogonal displacement amplification mechanism (such as bridge-type mechanism), in which the flexure hinges are generally axial load-dominated, whereas the deflection of traditional straight-axis flexure hinges is not related to the axial load under small deflection assumption. In this study, a bridge-type mechanism with circular-axis leaf-type (CALT) flexure hinges is designed, analyzed and validated. Through modeling the generalized displacements of CALT flexure hinge, the positive direction of its axis in the bridge-type mechanism is designed. The precise models of load relations for the CALT flexure hinges in the bridge-type DAM are established, and the multi-objective parametric optimization is further given. Small deflection-based static FEA results verify the generalized displacements’ models of CALT flexure hinge as well as the parametric optimization result. Compared with the corresponding bridge-type mechanism with the largest output displacement in the traditional researches, the output displacement of optimal result is improved effectively. For the design validation, the optimal design result is further applied to construct a piezoelectric-driven microgripper, which grasps parallelly and enlarges the output stroke simultaneously.

This study proposes a new mathematical model for the amplification ratio of a single-stair bridge-type amplification mechanism. To overcome the limitations of previous models, all members of the amplification mechanism are assumed to be compliant. The proposed model is compared to conventional models as well as analysis results using finite element models, after which the effects of the dimensions of each member are investigated. In addition, design optimization is carried out. Finally, the usefulness of this mathematical model is verified by an experiment using the optimally designed mechanism. As a result, the proposed mathematical model very aptly describes the displacement amplification ratio of the single-stair bridge-type amplification mechanism.

We study a parametric scatterer representing a quadripole of four bridge-type parametric circuits with antennas connected to the circuit arms and tuned to the pump signal and its half-wave subharmonic on the basis of simulation and full-scale experiments in the frequency range near 800 MHz.

The bridges built during the development of the Dutch road network after the Second World War are reaching their originally devised service life. A large subset of the Dutch bridge stock consists of reinforced concrete slab bridges. This bridge type often rates insufficient according to the recently introduced Eurocodes. Therefore, more suitable methods are developed to assess reinforced concrete slab bridges to help transportation officials make informed decisions about the safety and remaining life of the existing bridges. If information about a bridge is lacking, if the reduction in structural capacity caused by material degradation is unknown, or if an assessment shows insufficient capacity but additional capacity can be expected, a bridge might be suitable for a field test. A proof load test demonstrates that a given bridge can carry a certain load level. In the Netherlands, a number of existing reinforced concrete slab bridges have been proof loaded, and one bridge has been tested to collapse. Bridges with and without material damage were tested. These bridges were heavily instrumented, in order to closely monitor the behavior of the bridge. Critical positions for bending moment and shear were studied. Based on the proof load tests that were carried out over the past years, a set of recommendations for the systematic preparation, execution, and analysis of proof load test results is compiled. These recommendations will ultimately form the basis of the guideline for proof load testing for the Netherlands, which is currently under development.