Effect Of Stress On The Rail Ballast

The goal of the beam project is to design and construct a beam that can hold a given amount of weight without breaking. The beam is required to hold a concentrated load of 375 lbf on the X-axis and 150 lbf on the Y-axis. The maximum allowable weight of the beam is 250 grams. The maximum allowable deflection for the beam is 0.230 in. and 0.200 in. for the X and Y-axis respectively. The beam is required to be 24 in. in length, and it will be tested on a simply supported configuration spanning 21 in. All calculations are to be done under the assumption that the density of basswood is 28 lbm/ft3 and the modulus of elasticity for basswood is 1.46x106 lbm/in2. Given the constraints of a spending cost of $10.50, a maximum beam weight of 250 grams,

After the analysis on the first design brought to light the zero for members, it was decided that these members should be removed. In order to combat the flex of such a simple design the decision was made to double the thickness. This design would have the same outer frame of two triangles with a height of 20 centimeters and a width of 40 centimeters. Instead of being spaced five centimeters apart the wood be bonded directly together using Gorilla Glue. Balsa wood, a very lightweight wood with properties similar to a dense foam, was used for the main supporting member. Basswood, a lightweight yet firm wood, was used for the horizontal member. The final design added a triple layer sheet of balsa wood to rear side of the truss. This balsa sheet was added for the purpose of mounting and supporting the main structure. Additionally, a five centimeter square frame of bass wood was added at the end of the boomilever to place the loading block for testing. Once this design was implemented two key issues were discovered. First, due to the properties of the bass wood and balsa wood it was obvious that the placement needed to be reversed. The bass wood should be used for the hypotenuse and the balsa wood should be used for the

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.

When bridges are poorly constructed, they may fail due to load they carry, collision by derailed trains or even by vehicles that lose control leading to catastrophic incidences. However, if bridges are well-constructed, the chances or injury are greatly minimized in the event of an accident. Discussed in the subsections are the requirements of AS 5100 standards in relation to cable-stayed bridges and include design requirements for bridges, bridge aesthetics, bridge functional requirements, bridge component design requirements and bridge construction

Calculations were performed to determine the effectiveness of the design of the platform. Allowing for a safety factor of 1.5 times the design weight of 10kg and considering the bridge must not be overdesigned; plans were made for the bridge to fail at 25kg, 2.5 times that of the design weight. According to the calculations, the bridge would hold a load of over 15kg and experience failure at 20kg in the members. These calculations were later disproven in the testing, breaking 8kg earlier than expected, due to unforseen errors. An analysis of the bridge design and calculations has been included at the end of this report.

Furthermore, when the millennium bridge opened within the first weekend around 100,000 people had crossed the bridge. Due to such heavy traffic, this lead to something called resonance. Resonance is when the input vibrations frequency coincides with the natural frequency of the structure itself, causing large deflections to develop. The issue caused the bridge to undergo a swaying movement; hence led to its closure. After extensive research and analysis, it was found that the movement was caused by synchronized pedestrian footfall. To prevent this there were two options taken into account the lateral stiffening and the damping; both were used in order to increase the natural frequency of the structure so it did not match the footfall. In addition structures called fluid-viscous dampers and tuned mass dampers were installed to control both horizontal and vertical movements.

With respect to the diathesis-stress model, discuss two potential stresses (4 points) relevant to the case.

Proportioning the fascia boards in this manner will increase the rigidity of the handrail system and make handrail overturning less likely in the future

It is critical to use ballast over the ground foundation. The ballast keeps the rails off the ground and

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

During the construction, two half-spans being assembled 50 meters above ground level had a misalignment of 4.5 inches or 114mm in camber. It was suggested by John Holland & Constructions to use a kentledge to weigh down the higher section of bridge. It so happened that they had ten, eight tonne concrete blocks on site. These were placed halfway along the higher span to

Heavier trains requiring stronger track have resulted in striking increases in the weight of rails. Because of heavier trains, joints in the tracks have become fragile. Designing engineers have sought to reduce the number of joints by lengthening the rails. The customary length when locomotives were introduced was three feet, but in the 1830’s this was increased to fifteen or twenty feet. Early in the 20th century the most common length for rails was thirty feet, when 40-foot freight cars become generally available.

Superstructure bears the load that is being passed over the bridge and it transmits the forces caused by the same to substructure. Load received from the decking is transferred on to the substructure by Bearings. They also distribute the load evenly over the substructure material as it may not have sufficient strength to bear the superstructure load directly. Piers and Abutments are the vertical substructures which transfer the load to the earth in the foundation. Wing walls and returns are constructed as the extension of

Purpose: The purpose of this Physics Lab is to investigate what factors determine the amount of flexion of the cantilever. Hence, the objective is to establish a relationship between the length of a cantilever, which may give some insight into the physics of cantilevers.

Following tables and graphs show the result of the experiment. The tables will demonstrate the experimental and theoretical deflection for each case. The graphs will show the relationship between the load applied and deflection, in addition to compare the experimental deflection and theoretical deflection.