Residual Stress in Structural Steel Members Essay

This assignment will explore the concept of stress by firstly distinguishing between the definitions set out by Selye 919560 and Cox (1976). Following this assignment will critically evaluate the General Adaption Syndrome, SRRS and Daily Hassles explanations of stress and finally, conclude with a discussion on individual differences based on Friedman and Rosenman’s research.

The specimen ends were not thick or had moving wedge grips to keep it secure in the holders of the servo-hydraulic load frame. The movement of the specimen in the machine causes some of the data to be an inaccuracy. Also, the transverse strain causes issues with the strain gages that are called transverse sensitivity. The transverse sensitivity affects the accuracy of the data that is being collected for the transverse strain more than the longitudinal strain. This is greatly seen in the percent difference in the strain values such as in one case the Longitudinal strain was .4% while the transverse strain was 30%. Another issue with the strain gages was that if the strain gages weren’t properly placed on the specimen the data accuracy would

Overall, the 1018 and 1045 steel specimens displayed similar relationships between the heat-treating procedures. The 1045 steel had a greater tensile strength in all states except for the quenched state. In general, the 1018 steel specimens were more ductile than the 1045 steel specimens in all states.

Due to the assumptions that it demonstrates a linear distribution for plane strains throughout the laminate thickness and that out of plane strains can therefore be ignored.

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There are many variations of strain theory throughout sociology. However, all strain theories have largely drawn from the work of Robert K. Merton and his structural strain theory. Merton was largely influenced by Emile Durkheim and his theory of anomie (Tibbetts, 2010). During the 1930’s Merton began developing his own version of structural strain theory. It was during this time that the United States was experiencing the Great Depression, and as a result crime rates, unemployment, poverty, and suicide rates all saw a significant increase.

The above graph depicts the average Rockwell C Hardness achieved by each sample. This average disregards missing data or data that was noted as questionable. The graphed averages demonstrate the general trends of the different types of steels that were subjected to a heat treatment and quench media. Samples 1, 3, and 4 show a similar hardness after water quenching but differing characteristics during the other quenching types.

Pull each of the 18 welded specimens in tension using the Shimadzu brand tensile testing machine, with the special grips provided (Appendix A), in the order that the welds were performed

In contrast, there are a range of sociological theories that attempt to explain the cause of crime. One example of this is the ‘Structural Strain Theory’ developed by functionalist Robert Merton. This functionalist view states that societies are branded by both culture and social structure. Culture creates goals for people in society whilst social structure supplies (or fails to supply) the means for people to achieve those goals. In a well-integrated society people attempt to achieve these goals in an acceptable and appropriate way according to the explicit and implicit rules of that society. Therefore the goals and means in this society are balanced, however when an imbalance occurs, this is what causes deviant behaviour transpire. One paradigm that explains this theory is people who aspire to be economically successful (goal) will get a job to earn money (appropriate means of reaching that goal) and this type of person is called a conformist. However someone from a lower class who may not have the opportunity to receive a good education in order to get a job therefore they will surpass the acceptable means of reaching this goal. Therefore they are more likely to conduct deviant behaviour to reach this goal e.g. theft and this type of person is called an innovator according to Merton due to their acceptance of the cultural

Experiment Two: Stiffness Report from laboratory work performed on 12 May 2011 as a part of the unit of study CIVL2201 Structural Mechanics

The comparison of measurement and prediction of prestress losses in prestressed members is highly documented in literature. Hale et al. (2006) studied the prestress losses behavior of girders subjected to increased fiber stresses. They concluded that the previous AASHTO LRFD Specifications equations (2004) overestimated the prestress losses by roughly 50%. It was found that the NCHRP Report 496 (Tadros et al., 2003) equations predicted the losses to within an average of 6%. Currently, there have been quite a few investigations on empirical models for prestress losses for HSC. In a study conducted by Kowalsky et al. (2001) on several HPC bridge girders in North Carolina to determine the prestress losses of HPC girders. The researchers found shrinkage losses were a small component of the overall prestress losses and that the elastic shortening and creep losses were the main contributors. These larger than expected losses from elastic shortening and creep were because of a predicted modulus of elasticity that was higher than actual. The total prestress losses ranged from 12.9% to 19.1% of the initial jacking stress. In an investigation conducted by Tadros et al. (2003), seven full-scale bridge girders were instrumented in Washington, Texas, Nebraska and New Hampshire to determine the prestress losses of HPC girders. The total prestress losses measured were found to be lower than the AASHTO LRFD (1998) model. Modified expressions were proposed to AASHTO and later adopted in

The first process examined uses the Lablond Lathe machinery and requires a machined diameter of 7.7250, plus tight tolerances of + .0005 inches. A Process Capability Ratio (Cpk) analysis of the lathe’s data, results in a Cpk of .379 (exhibit A). A result of less than one indicates the machine is not capable of matching the tolerances laid out in the IMS spec. Therefore the Lablond Lathe is not suitable to handle the process it is being used for. Before a more suitable machine is selected, the Lablond Lathe should be checked for calibration, as should the measuring equipment used. If all fall within calibration specs, new

Steel products were defined by several attributes which determined the product application and defined quality. Grade described the metallic (chemical) composition of the steel, or the elements added to the basic recipe of iron and carbon to create the desired properties. Product described the shape of the product, including semi-finished shapes (blooms, billets and bars) and finished shapes (wires and coils). Surface finish described the smoothness and polish that could be applied to the material’s surface to enhance presentation. Size described the latitudinal and longitudinal dimensions of the product. Structural quality described the absence of breaks in the inner metallic structure. Surface quality described the absence of cracks or seams on the surface. Because specific applications called for specific attributes, many products were customized along one or more attributes for the customer. However, of all attributes, customers valued most the grade, which determined product performance.

ENGINEERED SYSTEM (MATERIAL) Lab Report 2 – Tensile Test Introduction ..........................................................................................................................................3 Objective .................................................................................................................................................3 Procedure: Carrying out experiment .........................................................................................3 Graphs......................................................................................................................................................4-6 Results......................................................................................................................................................

One of the primary mechanical fasteners that are currently used to connect structural steel members and to transfer loads between the components are structural bolts (Phares et al 2016). Now a days, various types of structural bolts are used in construction activities. But, the ASTM A307, ASTM A325, and ASTM A490 bolts the most common three types of structural bolts. Among the most common three types of structural bolts, ASTM A307 bolts are considered low-strength bolts, while ASTM A325 and ASTM A490 bolts are regarded as high-strength bolts (Kulak et al. 2001). As the main reasons of using structural bolts are to securely connect the structural members together and to transfer the loads to different members safely, the utilisation of structural bolts and their jointing techniques are a critical aspects of all the structures made of steel (Phares et al 2016). The success of a bolted connection of any structural members also depends significantly on the adequate tightening characteristics of bolts (Phares et al 2016). Therefore, the main objective of this research is to explore the various tightening characteristics of a high strength structural bolts made of high tension steel (alloy).