Estimate of Wave Overtopping Rate on Vertical Wall Using FUNWAVE-TVD Model

This study established a numerical model capable of calculating the wave overtopping rate of coastal structures by nonlinear irregular waves using the FUNWAVE-TVD model, a fully nonlinear Boussinesq equation model. Here, a numerical model was established by coding the mean value approach equations of EurOtop (2018) and empirical formula by Goda (2009), and adding them as subroutines of the FUNWAVE-TVD model. The verification of the model was performed by numerically calculating the wave overtopping rate of nonlinear irregular waves on vertical wall structures and comparing them with the experimental results presented in EurOtop (2018). As a result of the verification, the numerical calculation result according to the EurOtop equation of this model was very well matched with the experimental result in all relative freeboard (Rc/Hmo) range under non-impulsive wave conditions, and the numerical calculation result of empirical formula was evaluated slightly smaller than the experimental result in Rc/Hmo < 0.8 and slightly larger than the experimental result in Rc/Hmo > 0.8. The results of this model were well represented in both the exponential curve and the power curve under impulsive wave conditions. Therefore, it was confirmed that this numerical model can simulate the wave overtopping rate caused by nonlinear irregular waves in an vertical wall structure.

Numerical Analysis for layout methods on h-shaped double row piles

In this thesis, the numerical models of multi-stages excavation foundation pit with h-shaped double row piles as the retaining structure were built by finite element software PLAXIS 3D with HS small model as the constitutive equation for soil layers, then the numerical models for two different pile layout methods, parallel layout and staggered layout, were calculated, calculation results were compared. The numerical calculation result shows that back row piles stand most load, so they need to be strengthened during the design and construction process; the bending moment of back row piles at the position connecting with beam is the largest, which need to be strengthened; the h-shaped double row piles with staggered layout method is better than the parallel way, which could be used to improve the safety of engineering, as well as achieving economic rationality.

Functional Analysis of Bushing in Four-Link Suspension on K&C Characteristics Using Multibody Dynamics Method

The link of multilink suspension usually has bushings at both body connection and wheel carrier connection. These bushings are designed subjected to the function of link. In the studies of vehicle dynamics, bushing could be represented by three translational stiffness and three torsional stiffness as well as corresponding damping. Due to specific location and orientation of each bushing, usually only one of these six stiffness plays an important role. In this paper, effect of bushing on suspension K&C characteristics was investigated with a four-link suspension. Through virtual loading tests, force distribution of suspension bushing was studied to find the relation between bushing stiffness and K&C characteristics. In order to quantitatively measure effect of bushing stiffness on parasitic rate, an “equivalent force” method based on energy conservation was proposed. Similarly, an “equivalent displacement” method was proposed to measure effect of bushing stiffness on suspension compliance. According to theoretical analysis and numerical calculation result, six stiffness of a bushing could be classified into three categories: main function stiffness closely related to suspension behavior, sub-function stiffness affecting parasitic rate or subjected to large load and non-function stiffness to be controlled within an acceptable range.

The Electric Field Characteristics Analysis of Converter Transformer Considering Anisotropic

Simulation and analysis of the converter transformer valve side’s transient electric field by finite element method is proposed. The electric field of converter transformer valve side’s is calculated under polarity reversal condition, the maximum value of the electric field intensity of insulating materials and the potential distribution of the before and after first polarity reversal are given, obtaining the electric field distribution characteristics of the oil-paper insulation material in the case of isotropic and anisotropic before and after the first polarity reversal, and made a comparison. The numerical calculation result of the converter transformer valve side’s electric field is also given, and the comparison of the calculation results in the case of isotropic and anisotropic, for before and after the first polarity reversal is analyzed, obtaining the variation rule of the converter transformer valve side’s electric field and the variable factors which affected the distribution of the electric field.

The Effection of Stress Path on the Rock Relaxation Area of Large-Section Tunnel

Construction of large-section tunnel leads to changing of rock stress and comes about complicated stress-path, which causes continuously redistribution of rock stress with changing of stress path, leads expansion and change of plastic zone and brings relaxation-are avariation between left guide hole and right guide hole. The paper firstly introduced the construction situation of four-lane tunnel, and then analyzed its developments of design and construction at present. Relying on Dragon Head Mountain expressway tunnel with eight-lane and two way in Guangzhou, analyzed and discussed stress path, rock relaxation area effect on large-section tunnel by using site measured data from multi-displacement meter and numerical calculation result of rock relaxation area in different excavations. At the same time, verified the rational range of rock relaxation-area of large-section four- lane tunnel, which made the rock load of large-section tunnel to be studied further.

Analysis of Thermo-Mechanical Behavior of Shape Memory Alloys

Shape Memory Alloy (SMA) is widely used and plays an important role in various engineering fields due to its special characteristics of shape memory effect and super-elasticity. In this paper the phase transformation behavior and thermo-mechanics behavior of 50.0at%Ni-Ti SMA are investigated though differential scanning colorimeter (DSC) and tensional tests respectively. Optical micrographs show the transformation of austenite and twinned martensite. The comparing numerical calculation result with tensional test result shows the new macro-mechanical constitutive equation can express the thermo-mechanical behavior of SMA effectively.