The continuous two span footbridge has a uniform EI (100,000kNm^2) and carries a total load of 12kN/m over its entire length Following a recent flood both the left hand (A) and inner support (B) sink by 25mm. Using any method determine the moment over support B.

You are sitting in a rowing boat in a small pond, you have an unopened can of baked beans with you. If you throw the can (which sinks) into the pond what happens to the level of the water in the pond

www.amsterdamology.com

This question was plagiarized from Prof Peter Goodhew, thanks Mark

SOLUTION: The water level goes down! In the boat the mass of the can displaces its own mass of water (which is a lot of water as the beans are dense) when the can of beans sinks to the bottom of the pond they only displace their own volume which is small ( as they are dense) hence the water level goes down! Don't worry a beautiful illustration of the solution is coming soon.

I will be teaching you AR20389 Structures 2 from week 4- 11. I will cover several methods of structural analysis that you need to use in later courses in order to determine moments and forces developed in a structure due to the actions put upon it.

All of my notes are available through Moodle, this blog is a little added extra providing you with a weekly question based on the work covered in class its not compulsory but it will certainly help you understand the subject in time for the exam in Jan 2015!

For the statically determinate truss shown above determine the displacement at the point E (in mm).

Assume all members have the same EA= 10^5 kN and L=4m

You can solve this simple problem using virtual work. Firstly you must determine the forces in the truss (its determinate so just use statics once you have the reactions). Then find the forces in the truss caused by a unit load placed at the posit where ewe want to know the deflection (E).

Multiple the two set of forces together for each member (L/EA) and sum! You should get a displacement at E of 2.1mm - SOLUTION

For the statically determinate truss shown above determine the displacement at the point E (in mm).

Assume all members have the same EA.

You can solve this simple problem using virtual work. Firstly you must determine the forces in the truss (its determinate so just use statics once you have the reactions). Then find the forces in the truss caused by a unit load placed at the posit where ewe want to know the deflection (E).

Multiple the two set of forces together for each member (L/EA) and sum!

Hi everyone, its that time of year again. I will be uploading weekly questions for you all to attempt. These are not assessed but they will prepare you for the exam in January. If you are stuck on a certain question have look through the past 21 questions and the solutions !

Each week there will be a £5 prize for the randomly selected correct answer! This is open to anyone not just Bath students.

To help those students who are resisting Structures 1A and Structures 2 in August/Sept I will be uploading a question for each course on a regular basis .

Happy new year to everyone. The weekly blog questions will start again ready for Semester 2. In the mean time I hope you are all outside enjoying the snow. Why not try to build an ice sculpture.

For more inspiring ice structures check out this link to Hienz Isler's work.

The top and bottom chord of the long truss shown below are CHS sections, and each has I = 31x10^{6} mm^{4} and A = 6300 mm^{2}. Take E_{steel} = 200 GPa. All members have the same length of 1m. Determine the approximate deflection at mid-span.

The correct answer is 26mm. The truss can be approximated to a beam. The second moment of Area of the 'beam' can bedetermined using parallel axis theorem allowing standard beam deflection equations applied for an approximate answer.

Something a bit harder this week to keep you all on your toes!

What diameter of steel cable is required such that the mid-span deflection of the timber beam is only 50% of the mid-span deflection of the beam without the cable?