CIVE60002: Finite Element Analysis
Spring term 2024
Coursework
Individual or small group (max 2 students) assignment
A concrete gravity dam is to be investigated under the action of hydrostatic forces using plane-strain analysis. The curved side of the dam can be represented by a spline curve, as shown in the figure below.
Use Abaqus to establish the two displacement components at the top of the dam and the stresses at point (4,0) at the foundation level.
a) Discretise the dam cross-section into constant strain triangular elements with two meshes; the first is a mesh using elements of size (h=0.8m), while the second is a finer mesh using elements of size (h=0.4m). Apply your knowledge of the order of error for the constant strain triangle to obtain better approximation of the displacements and stresses. If these values are not within 5% of the fine mesh results, refine this mesh further until the 5% condition is satisfied.
b) Repeat the above procedure with the 6-noded quadratic triangular element, and compare against the constant strain element the number of freedoms required for 5% accuracy.
c) The dam is now to be considered resting on a sandy base with Es = 3.0×108 N/m2 and vs = 0.2. Using the coarse mesh of 6-noded elements (h=0.8 m) for the dam, consider the effects of a rectangular soil region with a centrally aligned width of 24 m and depth of 10 m, meshed with a varying element size (1.6 m at the top line and 3.2 m at the bottom line). Assume that the two vertical edges and the bottom edge of this region are fully fixed. Determine the effects of the soil on the displacements and stresses established previously. How would you assess whether the considered size of the soil subdomain is realistic in respect of these predictions?
Write a Report (max 10 pages) where you i) describe the problem, ii) present the methodology, iii) illustrate and discuss the results.
Submission deadline: Mon 18 Mar 2024 (week 25)
Report assessment: a) 35%, b) 30%, c) 35%.