Material Properties Of Steel And Concrete

Experimental stress analysis is a method of stress and strain testing of materials, to test for behaviour changes of materials under fatigue. The first method of stress analysis used was the Strain Gauge invented by Edward E. Simmons and Arthur C. Ruge created in the late 1930s to test for earthquake stress on elevated water tanks[1]. The creation of lasers and interferometry methods in the 1960s provided the basics of digital image correlation where high-speed cameras could be used to capture behaviour changes in materials during deformation. As the years went on, advancements in imaging, laser and sound technology allowed for new innovative techniques to be used to measure strain and stress. Some of these techniques include are digitised ultrasound images, non-linear least squares and robust stereo-vision system[2].

The test followed the standard procedure for tensile testing; force was applied to a specimen of known dimensions, and the resulting extension was recorded, thus allowing a stress-strain graph to be generated. The bottom of the specimen was secured into the crosshead of a tensile test machine, and the top secured to the load cell. An extensometer is placed on the specimen to measure extension. The test is complete when the force applied by raising the load cell at a constant rate causes the specimen to fail.

Proc., 7th Int. Conf. on Fracture Mechanics of Concrete and Concrete Structures. Korea Concrete Institute,

Engineering involves a wide array of problems that must be overcome. A great deal of time is spent researching materials and their properties. Materials compromise all aspects of our society, from buildings to roads to even the equipment that was used in this lab. Problems arise in regards to how strong or flexible the material is, with the official terms being stress, strain, and elasticity. Improper use of such materials results in tragedies such as the Tacoma Narrows Bridge in Washington that failed to due resonance and stress beyond its elastic limit [1].

Introduction: Bridges are constructed to withstand the forces of compression,tension,shearing,and torsion in a variety of ways. These consist of I beams , steel , arches, truss’s, bounded steel(suspension bridges) and even beams. Compression is the act when an object is being compressed or compressing , while tension is when an object is being stretched. Shearing in a bridge is when the bridge begins to bend , suspension bridges combat it very well. If built incorrectly bridges can undergo ,causing immense amount twist action to occur.

1) Of all the sample materials tested during the lab, the AISI-1020 Cold Rolled Steel was found to be the strongest. Moreover, between the two samples of AISI-1020 Cold Rolled steel, the sample without the neck was found to be stronger. This was observed by calculating the ultimate tensile strength for all the samples used during the experiment. As a result, the higher the ultimate tensile stress the material endured, the stronger the material was. The ultimate tensile stress calculated for the AISI-1020 Cold Rolled was 563 MPa which was the highest of all. Therefore, concluding that the AISI-1020 Cold Rolled without a neck region was the strongest material.

From tensile test, how the material will react to forces being applied in tension can be determined. As the material is pulled by machine, material’s strength can be found along its elongation.

The objective of this lab is to find the relationship between tensile stress and strain for various materials. The Stress-Strain Apparatus stretches (and in some cases breaks) a test coupon while it measures the amount of stretch and force experienced by the test coupon. Software is used to generate a plot of stress versus strain, which allows Young's Modulus, the elastic region, the plastic region, the yield point,

6, the modulus extracted from the experimental stress-strain curve of IPE360 profile changes from 197.50 GPa to 205.53 GPa and of IPE400 profile from 199.10GPa to 204.83 GPa as the longitudinal and transverse orientation, respectively. The mean of transverse specimen in this study is higher than longitudinal value, although the difference is small (2%). For the coefficient of variance found 0.024, which corresponds to a standard deviation of 4.81 GPa, which is summarized in Tab. 3. The specimen ID1 and ID3, which have different gauge lengths, widths and thickness and strain rate, are almost the same indicating that the gauge length may not have an effect on modulus, which is clearly shown in Fig. 6 and Tab. 3. Comparing the specimens ID1 and ID2, which have the same gauge length of 80 mm with strain rate 0.00007s-1 but different specimen orientation, it is seen that the modulus in longitudinal direction have 1.0% higher value than the transverse direction. Comparing the specimens ID1 and ID4, which have different gauge lengths, width, thickness, the variation of average measured modulus is 2.5 GPa for all strain rate, indicating the effect of varying parallel length, gauge width, grip area and orientation of specimen. If the variations that occurred during machining and testing are taken into account, it would be reasonable to suggest that the varying geometry does not have a significant effect on the modulus of structural steel. Additional, it is seen that the measured

Reinforcing steel and prestressing tendons 5. Structural welding: Periodic Visual Inspection [ ] Single pass fillet welds 5/16” [ ] UT all PP groove welds in column splices [ ] UT all PP groove welds in column splices >3/4 [ ] UT column flanges at beam flange welds [ ] Other: 6.High Strength bolting: Snug Tight: [ ] All [ ] As indicated Full Pretension: [ ] All [ ] As indicated 7. Structural masonry: f’m = , Stresses Verification of f’m [ ] Prism tests [ ] Prism test record [ ] Unit strength [ ] Continuous inspection [ ] Periodic inspection Structural masonry continued: Test: Before During Prism [ ] [ ] Units Grout Mortar [ ] [ ] [ ] [ ] [ ] [ ] 8. Reinforced gypsum concrete: [ ] Continuous inspection of mixing and placement [ ] Periodic inspection: [ ] Strength testing: 9. Insulated concrete fill: [ ] Periodic inspection [ ] Placement inspection [ ] Strength testing [ ] Stressing and grouting of tendons 10.

The failure compressive load was recorded for each specimen, and the corresponding tensile strength was calculated.

In fact, the majority of available studies have concentrated largely on small cross-section dimensioned columns with a section aspect ratio of less than 2.0. The width and depth of their cross-sectional dimensions were varied in the range between 100 mm and 300 mm. In addition, the studies have greatly focused on smaller scale columns of typically 300 to 500 mm in height. However, Tan (2002) developed a monotonic model to assess the strength enhancement of FRP confined half scale rectangular columns with a section aspect ratio of about 3.65, representing only columns in the monolithic housing apartments. Of the few papers published to data on cyclically loaded plain concrete columns, Abbasnia et al. (2013) investigated the cyclic stress-strain behavior of 12 FRP-confined unreinforced concrete prisms of size 120×180×300 mm (aspect ratio 1.50), and 90×180×300 mm (aspect ratio 2.0). The earlier research conducted by Hany et al. (2015) has included both experimental and analytical approaches for investigating and predicting the axial stress-strain behavior of unreinforced concrete specimens of size 140×180×500 mm (aspect ratio 1.28), and 130×200×500 mm (aspect ratio 1.54). Such small size specimens may be stiffer than to be strengthened with FRP-techniques (Pessiki et al. 2001).

Ahlbeck et al. (as cited in Sun & Dhanasekar 2002)[4] point out that that stress distribution (stress response) under concrete sleeper is Trapezoidal shape uniformly until the foundation as demonstrated in Figure 2.1.1 and the stress distribution angle (internal friction angle) of the rail ballast has effect on the stiffness the damping of the upper and the lower divisions of the rail ballast.

The finite element method is a numerical technique that has been successfully adopted to study special cases where, for instance, stress-strain distribution is required. In the past, due to the complexity of the problems, it was difficult to describe them in the same manner because they took much time and effort. However, the development and the use of sophisticated software have now improved this situation. (Zienhiewicz, 1977)

Problem 111 For the truss shown in Fig. P-111, calculate the stresses in members CE, DE, and DF. The crosssectional area of each member is 1.8 in2. Indicate tension (T) or compression (C).