Specimen 5 Lab Report

This document’s purpose is to look for various available bracings used in a steel structure, which can be applied during construction to prevent the building from succumbing to the damage occurred due to the lateral movement, vertical movement, oscillatory movement, etc. caused by the seismic forces such as earthquake force and also forces such as wind load acting laterally.

Depending upon the number of levels of outriggers and their stiffness, the perimeter columns of an outrigger structure perform a composite behavior with the core. When compared to single-storey outrigger structures, multi-storey outriggers have better lateral resistance, and thus efficiency in the structural behavior. However, each extra outrigger storey enhances the lateral stiffness, but by a smaller amount than the previous

Abstract—The design of tall and slender structures is controlled by three governing factors, strength (material capacity), stiffness (drift) and serviceability (motion perception and accelerations), produced by the action of lateral loading, such as wind and earthquake. Outrigger systems are generally very effective in fulfilling the serviceability requirements of tall buildings. This research conducted a study on effectiveness of outrigger truss by simplified method to introduce the normal buildings that can be minimized the deflection as the buildings with outrigger. Two and three outrigger levels are used in 40 and 50 storey square shape buildings respectively. From this result, the engineers can run the buildings without using outrigger to get the minimum deflection as the buildings with outrigger but the base shear is larger than outrigger buildings significantly. Therefore, for the proposed buildings to get minimum deflection, the outrigger is more effective than simplified method.

In this experiment the main aim was to modelling a frame subjected to multiple loading conditions and record how the force and strain vary to different loads. The frame represented a simple roof trusses and the loading conditions are similar to what a typical roof would undergo. In this experiment a universal fame was used with load cells to provide the load and digital force and strain instruments to record the data. As the load was increased the strain went up linear showing a linear relationship between loading and strain. After analysing results it was found that the

Flexural-tensile tests were carried out according to GBT 1456-2005, i.e., "Test method for flexural properties of sandwich constructions"[16]. In this part, 11 specimen groups are involved, and every group consists of 5 specimens with an average size 400 mm × 150 mm and an average honeycomb grid size of 6 mm. Compared to the flat compressive test, besides the effects of the material and thickness of the face layer and core layer, the effect of the core layer layout on the flexural-tensile properties was also taken into consideration. Two different layouts, L-type and W-type, were designed, among which L-type layout denotes that one side of the honeycomb cell is parallel to the length direction of specimen, whereas W-type distribution denotes that one side of the

The weight of a building is transmitted to the ground through its foundation when it is being constructed and this added stress to the underlying strata. The stresses added can cause

The collapse of this structure was mainly attributed to improper calculations and anticipation of the possible errors in the design employed. According

Fonte et al in 2006 [3] Suggested that Most of catastrophic mechanical failures in power rotor shafts occur under cyclic bending combined with steady torsion: Mode I (ΔKI) combined with Mode III (KIII). An analysis of the influence of steady torsion loading on fatigue crack growth rates in shafts is presented for short as well as long cracks. Long cracks growth tests have been carried out on cylindrical specimens in DIN Ck45k steel for two types of testing: rotary or alternating bending combined with steady torsion in order to simulate real conditions on power rotor shafts. The growth and shape evolution of semi-elliptical surface cracks, starting from the cylindrical specimen surface, has been measured for several loading conditions and both testing types. Short crack growth tests have been carried out on specimens of the same material DIN Ck45k, under alternating bending combined with steady torsion. The short crack growth rates obtained are compared with long crack growth rates. Results have shown a significant reduction of the crack growth rates when a steady torsion Mode III is superimposed to cyclic Mode I. A 3D Finite Element analysis has also shown that Stress Intensity Factor values at the corner crack surface depend on the steady torsion value and the direction of the applied torque.

1. Diagonal cracking mode (DK mode): In this case a diagonal strut is formed between two loaded corners and the failure occurs between these corners by formation of diagonal tension crack as shown in Fig.1.1-a. This mode often happens in weak frames with infill having strong mortar (Experimental and Analytical Seismic Evaluation of Concrete Masonry-Infilled Steel Frames Retrofitted using GFRP Laminates; Mehrabi and Shing 1997).

In almost every structure, beams or flexural members are found. It is important then to understand how different beams will reach to different situations. To evaluate flexure and stress distribution in a simple beam, seen in Figure 1, a fundamental four point bending test can be conducted to induce pure bending on the center of a wide flange shape beam.

The test specimens were divided into three series (R1.5, R2.0 and R2.5) on the basis of cross-sectional aspect ratio, and complete details of the test columns are summarized in the table 1 and Fig. 1. The specimen identification convention, which are utilized in Table 1, is in accordance with the first letter R defining the rectangular column. In addition, the following numbers 1.5, 2.0, and 2.5 refer to different sets of cross-sectional aspect ratios. The following letter and number refer to the volumetric ratio of hoop (H) reinforcement with 0 denoting plain concrete, 1, and 2 denoting transverse reinforcement of 0.3 and 0.6% volumetric ratio, respectively. The third last symbol L and number following it refer to the number of layers of CFRP wrap. The final symbol in the specimen identification of M or C refers to monotonic uniaxial loading and complete unloading/reloading of cyclic axial loading patterns. In this paper, complete unloading/reloading refers to unloading from the envelope curve to zero stress followed by reloading to the envelope curve. For further clarification, R2.5H2CL4, for example, had aspect ratio 2.5 and hoop steel reinforcement ratio 0.6% .As well, before it was tested under cyclic axial compression loading, this specimen was externally confined with four layers of CFRP material.

The tensile force transferred from the steel bar through the bond to the concrete is illustrated and compared for difference reinforcement ratio (ρ = 0. 5%, 0.89% and 1.12% for steel 12 mm, 16 mm and 18 mm) in figure (5.79) and table (5.17). Before first crack accured (Pre-cracking stage), the precentage of tensile force transferred from the steel bar to the concrete accounts is about 8%, 13% and 16%. Aftere first crack accured (cracking stage), the precentage of tensile force transferred from the steel bar to the concrete is about 53%, 60% and 72%. During Post-cracking stage almost all the tensile force is carried by the steel bar 82%, 89% and 90% for P-12- FEM, P-16-FEM and P-18-FEM respectivily.

Adorno (2004) developed his studies using Concrete and reinforced concrete submitted to straight flexure-compression with the same dimensions. Their experimental program was divided into two Series, PSA (non-reinforced columns) and PCA4 (strengthened columns). They are shown in Figures 2.14 and 2.15. Although the PSA series is made of simple concrete columns, a Nominal diameter equal to five millimeters, was used at the ends of the models, with the Purpose of avoiding localized ruin of these regions, because of the concentration of stresses. Adorno (2004) concluded on the rupture load and the ultimate moment that:

Over the past quarter century, many of both the experimental and analytical studies have increased dramatically on the monotonic behavior of FRP-confined concrete columns, and as a result, many axial stress-strain models have been proposed; however, most of them have focused largely on FRP-confined plain concrete cylinders numerous people tested (e.g., Mirmiran and Shahawy 1997; Mirmiran et al.1998; Xiao and Wu 2000; Lam and Teng 2002, 2003; Berthet et al.2005; Almusallam 2007; Benzaid et al.2008; Eid and Paultre 2007, 2008; Teng et al.2009; Smith et al. 2010; Cui et al.2010). A certain number of these researches have included non-circular unreinforced (plain) columns (e.g., Rochette and Labossiere 2000; Ilki and Kumbasar 2002; Youssef 2003; Rousakis et al.2007; Youssef et al. 2007; Benzaid et al.2008; Wu and Wei 2010; Wu and Zhou 2010; Benzaid and Mesbah 2013). Owing to the limited progress of the experimental investigations carried out on FRP-confined non-circular reinforced concrete columns (RC) tested under cyclic axial compression loading, a well-defined study indicates that a few essential gaps need more further research. As a result, the current study aims to consider the most significant issues, namely, the influence of 1) cross-sectional aspect ratio, 2) internal hoop or longitudinal steel reinforcement ratio, and 3) cyclic or monotonic compression loading pattern. These issues which form the basis of the experimental program on CFRP-confined rectangular reinforced

Sandwich panels are usually designed as one-way structural elements; shear forces are generated due to longitudinal bending in the panels. In addition, the shear connectors may be used to transfer the weight of a non-structural wythe to the structural wythe. Shear connectors that are designed to be stiff in one direction and flexible in another are called one-way shear connectors [4]. Examples of these are longitudinal steel-wire trusses, solid ribs of concrete, flat sleeve anchors, fiber composite rectangles, and small-diameter bent bars (Fig.1.1). Care should be taken in the manufacturing process to maintain the preferred orientation of one-way connectors. Some shear connectors are stiff in at least two perpendicular directions and will consequently transfer in both longitudinal and transverse horizontal shear. Examples of these are solid zones of concrete (often located at each end of the panel and at lifting points), connection plates, cylindrical sleeve anchors, and crown anchors. Connection plates and crown anchors are normally installed in solid zones of concrete and therefore it can be considered as rigid shear connections