Applied Mechanics and Materials Vols. 764-765

Abstract: This study is aim to evaluate the dynamic response variation of the scale-down reinforced concrete frame specimen under accelerated corrosion conditions. The specimens achieved the accelerated corrosion test by immersing in the accelerated corrosion test. Open circuit potential, corrosion rate, natural frequencies, displacements, accelerations and response spectral curves were tested and discussed. Test results presented that the corroded reinforced concrete specimens presented the changes in the dynamic response especially natural frequencies and response spectrum. This study provided further insight on the variation of seismic response behaviors in the deteriorated reinforced concrete structures and hoped to useful for structural assessments and appraisals applied to full-scale structures.

Abstract: A 1/25 scale-down specimen was constructed of a reinforced concrete reactor building used in the nuclear power plant. The non-demoulding technology and self-consolidating concrete were used to cast the specimen with a length of 2.9 m, width of 2.9 m, height of 2.9 m and weight of 28 tons. The entirety struc-ture was composed of a primary containment (thickness of 10 cm), a secondary containment (thickness of 7.5 cm) and three floors (thickness of 30 and 15 cm). Shaking table tests were conducted on it in the National Center for Research on Earthquake Engineering. Testing results indicated that the scale-down specimen kept the structural integrity under a 0.6 g specific seismic wave hit. In addition, the ETABS model accurately represented the dynamic characteristics of the scale-down specimen by numerical method obtained the conservative results.

Abstract: The use of steel-concrete composite members has been significantly increased as they have the advantages of the reduction of cross sectional areas, excellent ductility against earthquake loadings and a longer life span than typical steel frame members. In this paper, push-out tests were performed on six specimens to investigate the structural behavior and shear strength of perfobond connection of a steel-concrete composite slim floor system. An equation to theoretically estimate the shear strength of the perfobond connection is proposed, and its accuracy is examined by comparing its predictions with the test results. A finite element analysis model is also developed and used to confirm the effectiveness of the proposed strength equation.

Abstract: In the present study, a detailed vehicle–bridge dynamic interaction model is established, and the bridge is modeled as laminated composite beams which are discretized as finite beam elements. The vehicle-induced responses of the bridge in the damaged state are used as input data for damage identification and the response sensitivities with respect to the damage indices of the elements are calculated to establish the sensitivity matrix. Based on the error between the measured response and the computed one as a minimization criterion, the sensitivity equation is solved by the least-squares method, and then the damage is located and quantified with the finite element model updating technique. It can be concluded that only one measurement point is required to detect the damage of the bridge, and location of the measurement point does not significantly affect the identification result. Furthermore, it is noted that the absolute damage of any beam element is well identified by using either the displacement response, velocity response or acceleration response.

Abstract: The paper includes conclusions from evaluation of results obtained from long-term measuring of innovative atypical roof timber structures. Based on the results of measurements of vertical and horizontal deformation components it is possible to analyze the real behaviour of structures in given conditions. By assessing deformations in various stages, including particularly external and internal environment temperatures, relative air humidity and wood moisture content, decisive parameters for real structure behaviour can be established. The data processed are from period 2001 – 2013.

Abstract: Seismic provisions have utilized design eccentricities to reduce planar irregularities in lateral stiffness of buildings. In calculating a design eccentricity, the dynamic amplification factor may be applied either to accidental eccentricity or to both inherent and accidental eccentricities according to design codes. In this paper, different code provisions and their impact on torsional responses of buildings are investigated using example buildings with various aspect ratios and eccentricities. It was found that dynamic amplification is underestimated if the inherent eccentricity is small, when buildings are designed by seismic provisions using dynamic amplification factors for both to inherent and accidental eccentricities. On the other hand, the design eccentricity determined by applying the dynamic amplification factor only to accidental eccentricity reflects torsional amplification accurately.

Abstract: The sewage comes from buildings is drained into public sewers. The sewage is then treated in a sewage treatment plant to meet the sanitation standards before being discharged to the water cycle in nature. The sewage treatment process consumes energy and produce CO₂. In this research, the idea of streamlined life cycle assessment was applied. The CO₂ emission of sewage treatment was assessed from direct energy consumption of four major sewage treatment plants in Taiwan. The results show that the unit CO₂ emission of sewage treatment calculated from four plants is 0.174 kg-CO₂/m³. The CO₂ emission at in-plant sewage treatment stage takes more than 95% of total CO₂ emission for most plants. The results suggest that CO₂ emission of sewage treatment can be calculated from energy consumption at in-plant sewage treatment stage to simplify the calculation. This database will be important reference for water resource research.

Abstract: This study investigated vertical connector performance of modular roadway slab. A modular roadway utilizes precast members of slabs and crossbeams under the slabs, and the connection between them is critical. The vertical connector has to resist horizontal loads and allow the thermal movements. In the preliminary study, two boundary conditions were investigated to identify the better vertical joint functionality. Based on the results, detailed analysis models were developed and displacements and internal forces of the vertical connector were investigated. The analysis results showed that for the given modular slab and developed vertical connector, the vertical connector provides better stability and functionality but required 80 kN of horizontal shear forces.

Abstract: Most of current concrete design codes require that critical sections should be reduced in the presence of openings near columns to consider their effects on the punching shear strength of reinforced concrete flat-plate slabs. For example, ACI 318-11 stipulates that a part of the perimeter enclosed by two projection lines from the centroid of the column to the boundaries of the openings shall be considered ineffective. However, the direct application of this rule to practical cases may be rather complicated depending on the geometrical layout and shape of columns and openings. In this paper, simple mathematical formulations are proposed to evaluate the ineffective part of critical sections due to openings. This approach can be applied to the design of reinforced concrete flat-plate slabs based on ACI 318-11. A numerical algorithm is also developed to handle general cases where the ineffective parts of multiple openings overlap with each other.

Abstract: The dynamic response of non-uniform Timoshenko beams made of axially functionally graded materials subjected to multiple moving point loads is studied by using the finite element method. The material properties are assumed to vary continuously in the axial direction according to a power law. A beam element, taking the effects of shear deformation and cross-sectional variation into account, is formulated by using exact polynomials obtained from the governing differential equations of a homogenous Timoshenko beam element. The dynamic responses of the beams are computed by using the implicit Newmark method. The numerical results show that the dynamic characteristics of the beams are greatly influenced by the number of moving loads. The effects of the distance between the moving loads, material non-homogeneity, section profile as well as aspect ratio on the dynamic response of the beams are investigated in detail and highlighted.