ENGINEERING TRIPOS PART IIB - 2011/2012
Module 4D6 - Dynamics in Civil Engineering
Dr G Madabhushi
3D7 assumed; 3D2 and 3D4 useful
14 lectures + coursework
||Material / Format / Timing / Marks
Lecture Syllabus / Written exam (1.5 hours) / Start of Easter Term / 75 %
Coursework / 2 Reports / due middle and end of Lent Term / 25 %
This module is an introduction to the behaviour and design of civil
engineering structures subjected to time-varying loads. Earthquake-resistant
design, dynamic soil-structure interaction, machine foundation design, blast
effects on structures and the fundamentals of wind engineering will be
STRUCTURAL DYNAMICS (4L)
Linear Elastic Dynamics
- Introduction to dynamic
loads in Civil Engineering; dynamic amplification factors.
single-degree-of-freedom analysis of complex structures; sway frames;
structures with distributed mass.
- Rayleigh's principle;
natural frequency of simple systems using energy methods.
- Linear models to represent
structures and their relevance; analysis in frequency domain; mode
- Modal analysis of
vibration; use of finite element packages.
- Sources of nonlinearity in
structures and foundations.
- Analysis in time domain;
numerical integration of equations of motion.
APPLICATIONS OF DYNAMICS IN CIVIL ENGINEERING STRUCTURES
PART A: Soil-Structure Interaction (5L)
- Machine-induced vibrations;
active and passive vibration isolation.
- Simple analytical models;
design of machine foundations with active isolation, protection of
sensitive buildings with passive isolation.
- Earthquake loading on
structures; response and design spectra.
- Structures subject top
ground motion; deformations due to lateral accelerations; Newmark's
sliding block analysis' concept of threshold acceleration.
- Foundations effects;
stiffness of soil foundation and soil-structure interaction.
- Pore pressure build-up
during earthquakes; partial liquefaction; degradation in soil stiffness;
non-linear soil models.
- Liquefaction resistant
design, simple examples.
PART B: Seismic resistant design, blast effects and wind engineering(5L)
Seismic resistant design
- Structural design and
- Physics of blasts; blast
effects on structures; blast-resistant design.
- Nature of wind.
- Wind forces on structures.
- Response of structures to
buffetting. Fluid-structure interaction (vortex-shedding, galloping and
flutter). Long-span bridge case study.
Seismic analysis of an existing tall building using the ABAQUS finite
element package and a study of the effect of foundation softening on the
overall structural response. Total time 8 hours.
On completion of the module students should:
- Be able to identify cases
where a static model of a structure is inadequate, and a dynamic model
should be used;
- Be able to produce a simple
estimate of the natural frequency and fundamental natural mode of any
- Be able to estimate
linear-elastic spring parameters for a given foundation;
- Be able to compute the
natural frequencies and natural modes of structures using the ABAQUS
package and include simple soil models to account for soil-structure
- Be able to estimate the
response of complex linear-elastic structures to earthquakes using modal
superposition and the response spectrum;
- Be able to use elastic and
inelastic design spectra, and to understand their form;
- Be able to perform simple
designs for vibration isolation;
- Be able to perform
simplified soil stiffness calculations accounting for partial
liquefaction, and to use this approach in simple liquefaction resistant
- Be able to describe some
standard methods of seismic-resistant structural design;
- Be able to describe blast
processes and their effects on structures;
- Be able to appreciate the
factors involved in the estimation of wind climates and of structural
response to wind;
- Be able to understand the
various measures that characterise atmospheric turbulence;
- Be able to anticipate the
circumstances under which aeroelastic phenomena may be problematic;
- Be able to estimate the
dynamic response of a tall structure in a given wind environment;
Please see the Booklist for Group D Courses for references for this module.
Last updated: August firstname.lastname@example.org