Open Ended Lab

Open Ended L ab. Present by :- Numan Ahmad (2021-CIV-71) Abdul-Muqeet (2021-CIV-81) Hassan Shahzad (2021-CIV-83) Hussain Iqbal (2021-CIV-84) Asad Ali (2021-CIV-86) Ameer Hamza Asif (2021-CIV-87) Muhammad Sami (2021-CIV-103) Mohamed Omar Abdi (20-R/19-CIV-296).

Job Description. As per project drawings, Structural bolts (A307 and A325) along nuts and washers are to be used for testing. The consultants representaive at the site must ensure the quality of the mentioned components. You as the constructor’s representative must provide the test results of the components in the form of report that satisfies the requirement set in relevant standards..

Bolts. Bolts are the main members for a junction between two specimens. Bolts we used were bought from market as per given standard. The samples we used are shown below.

Nuts. Nuts are almost always used in junction with a bolt to fasten multiple parts together. Hex finish nuts are used for fastening to a hex cap screw, socket cap screw, or bolt. Nuts we used are also bought from the same same supplier from which we bought boults but that were not of good quality..

Washers. Washers are also used along with nuts to provide a gripped fastening against boults. To avoid slippage of nuts by axtra tightning washers provided inbetween nuts and boults as shown below.

ASTM Standards. Following are the relevant standards for nuts, bolts and washers; ASTM A325 This standard is mostly used for making of bolts used in communication tower. This specification covers two types of quenched and tempered steel heavy hex structural bolts having a size over 1.0 to 11 2 ⁄ in., inclusive. ASTM A307 This specification covers the chemical and mechanical requirements of two grades of carbon steel bolts and studs in sizes 1 4 ⁄ in. through 4 in..

Hardness Test on Bolts, Nuts and Washers. Objective of Experiment: The objective of this experiment is to determine the hardness of bolts, nuts and washers. Apparatus: Rockweell Hardness Testing Machine Samples Basic Infromation :- You can get the idea of range of ultimate strength of certain materials by hardness test using these relations; ?? = 3.45(?. ?)???; ?? = 0.50(?. ?)??.

Hardness Test on Bolts, Nuts and Washers. HARDENING TEST ON WASHER HARDENING TEST ON NUTS.

Tension Test on Bolts. Objective of Experiment: To study the stress-strain behavior of bolts of relative standards. To determine the mechanical properties in bolts. To check the adequacy of bolt as per standard. Apparatus: 500KN Shimadzu Universal Testing Machine Vernier Caliper (L.C 0.05mm) Bolts.

Tension Test on Bolts. Necking:- Localized decrease in cross-sectional area of sample after the ultimate strength is called Necking. Necking continues up to the failure of the material. Due to necking (cup and cone shape formation) the cross-sectional area is reduced. Typical necking of the specimen we used is shown below.

Tension Test on Bolts. Stress ~ Strain Curve:-.

Tension Test on Bolts. Proportional limit , elastic limit, y ield point , u ltimate Strength/Tensile strength.

Results. A325 Yield Strength 136.65KSi 81Ksi (min.) Ultimate Tensile Strength 138.87Ksi 105Ksi (min.) %age Elongation 41.6 14 (min.).

Conclusions. We preformed two experiments on the same specimen, one was tension and the other was hardness test. On the basis of these experiments we computed two table in which we compared our calculations with the standards. We purchased bolts from market, the shopkeeper claimed these are of grade 8.8. Then we performed both experiments on the specimen (nuts, bolts, washers) and performed calculations on the experimental measurements. Then we compared our calculations with standards (ASTM A307). In the end we came to know that the nuts, bolts, washers are of grade 8.8. The whole section was into 5 groups. All were asked to buy their specimen of same grade but from different shops. All of the groups performed the same experiments. Although in the end they all come to know that their specimens are of grade 8.8 but there was a difference in the calculated values of these groups. This difference was due the difference of material..

Thank You - Typewriter image.