Dynamics of structures

PART 1 DEALS WITH THE DYNAMIC ASPECTS OF THE SUBJECT: MATHEMATICAL ANALYSIS OF SYSTEMS SUBJECTED TO INDEPENDENT VIBRATIONS BY MEANS OF MATHEMATICAL MODELS. THE ANALYTICAL SYSTEMS USED ARE NON-LINEAR SYSTEMS, HYDRODYNAMICS AND NUMERICAL METHODS. PART 2 EXAMINES SEISMIC MOVEMENTS, THE DYNAMIC BEHAVIOUR OF STRUCTURES AND THE BASIC CONCEPTS OF THE SEISMIC DESIGN OF STRUCTURES.

Fundamentals of earthquake engineering

Ordinary differential equations of the first order linear differential equations complex numbers and linear algebra simultaneous linear differential equations numerical methods the descriptive theory of nonlinear differential equations mechanical systems and electric circuits Fourier series Fourier integrals and Fourier transforms the Laplace transformation partial differential equations Bessel functions and Legendre polynomials applications and further properties of matrices vector analysis the calculus of variations analytic functions of a complex variable infinite series in the complex plane the theory of residues conformal mapping.

Advanced Engineering Mathematics. By C. R. Wylie. Pp. xiv, 813. 1966. (McGraw-Hill.)

Problem Given the number of times in which an unknown event has happened and failed: Required the chance that the probability of its happening in a single trial lies somewhere between any two degrees of probability that can be named. SECTION 1 Definition 1. Several events are inconsistent, when if one of them happens, none of the rest can. 2. Two events are contrary when one, or other of them must; and both together cannot happen. 3. An event is said to fail, when it cannot happen; or, which comes to the same thing, when its contrary has happened. 4. An event is said to be determined when it has either happened or failed. 5. The probability of any event is the ratio between the value at which an expectation depending on the happening of the event ought to be computed, and the value of the thing expected upon it’s 2 happening.

An essay towards solving a problem in the doctrine of chances. [Facsimil]

Ground-borne vibration due to static and dynamic axle loads of InterCity and high-speed trains

Development and experimental validation of a numerical model for the prediction of ground vibration generated by pavement breaking

Recent flood events in central Europe accompanied by the failure of river dykes have shown a clear need in effective and reliable methods to survey and monitor the structure of earth-fill dams. Among the geophysical techniques the imaging of the electrical resistivity is used in most cases, occasionally ground penetrating radar is applied in the frame of the search for subsurface facilities, seismic methods are rarely used. This paper focuses on the multichannel analysis of surface waves method (MASW) to determine elastic soil properties and aims to extend its application field to dyke and dam structures. An elaborated testing campaign was conducted and provided the chance to collect experiences in the practical use. Test results obtained at one test site are selected and presented in comparison with the conclusions from borehole logs. A remarkable relation between the shear wave velocity and the consistency of the clay liner was found. Valuable additional information on the composition of dyke body and base could be obtained. Possible influences of the dyke's topography on the test results were studied by means of a numerical analysis which showed the principal applicability of standard processing procedures.

Application of Surface Waves for the Geotechnical Characterisation of Dykes

Pavement breaking generates a high level of ground vibration that is potentially damaging to nearby buildings and infrastructures. In this paper, a numerical model for the estimation of the impact load due the blow of a falling-weight pavement breaker is first developed. The est imated impact load is in good agreement with the experimental result. Next, the fracturing of the concrete road is investigated and the amount of dissipated energy is found to be only a small fraction of the impact energy. The large part of the impact energy is transferred to the soil and causes ground vi brations. Finally, a non-linear road-soil interaction model is developed and numerically verified. The model accounts for both road-soil separation as well as the inelastic behaviou r of the soil. The model is used to predict ground vibrations generated by the operation of a multi-head pavement breaker. Up to 25m from the road, the predicted ground vibrations agree with the experimental results while at large distance s the model underestimates the response. Keywords—pavement breaking, ground vibration, fallingweight impact, non-linear road-soil interaction

Prediction of ground vibrations generated by a falling-weight pavement breaker

The size effect is a phenomenon where the strength and the ductility of a material depend on the size of the structure. Investigating size effects and related crack formation in brittle materials requires advanced monitoring methods. The aim of this research is to experimentally investigate the impact of size effect with the acoustic emission (AE) technique. Brazilian splitting tests with AE monitoring were performed on cement-based mortar cylinders of three sizes. It was found that in addition to the size, the boundary condition affects the final strength. When adopting similar boundary conditions in samples with different sizes, the larger samples had the lowest tensile splitting strength. For the larger samples, initially, there were fewer AE activities. However, there was a surge of high-amplitude AE events near the peak load. This indicates that as size increases, there is a lack of micro-cracking before macro-crack propagation, and the material fails in a more brittle manner. The width of the fracture process zone was quantified with AE and increased with sample size. A further analysis of the AE amplitude distribution demonstrated a change in the distribution in the pre-peak phase for the larger samples and for the smaller samples in the post-peak phase, signifying the brittle to ductile failure transition that occurs as size decreases.

/pdf/acoustic-emission-analysis-of-fracture-and-size-effect-in-1etjf86i.pdf

Acoustic Emission Analysis of Fracture and Size Effect in Cementitious Mortars

https://lirias.kuleuven.be/bitstream/123456789/498379/1/slides.pdf

Stijn François

Papers

Development and experimental validation of a numerical model for the prediction of ground vibration generated by pavement breaking

Application of Surface Waves for the Geotechnical Characterisation of Dykes

Prediction of ground vibrations generated by a falling-weight pavement breaker

Acoustic Emission Analysis of Fracture and Size Effect in Cementitious Mortars

Railway induced ground vibration