Wei Qing Liu

Rocking Response of a Surface-Supported Strip Foundation under a Harmonic Swaying Force

This paper presents an accurate analytical method to obtain the rocking impedance function of a surface-supported strip foundation. The Green’s functions of the elastic half-space under concentrated or uniform loads with infinite length are derived and an elaborate integration method is used to calculate the multi-value improper integral. The interface between the foundation and the supporting medium is divided into a number of strip units. The rocking impedance function is solved by adding the moments in every strip, based on the fact that the vertical displacement of each unit can be uniquely determined by the rotation amplitude of the rigid foundation. Excellent convergence has been observed. Comparing the numerical results to those obtained by the thin layer method, good agreements are achieved. Finally, the effect of the Poisson’s ratio on the rocking impedance function of the strip foundation is discussed in detail.

Study on the Arrangement of Baffles Attenuating Blast Waves inside Tunnels

Explosion inside the entrance of a tunnel may produce strong blast wave in the tunnel. Taking effective measures to attenuate the air blast wave is very important. Numerical simulations were done on explosion inside the entrance of a tunnel in three different cases, no baffles, symmetrical baffles and stagger baffles arranged along the tunnel. It is found that the arrangement of baffles can attenuate the air blast wave effectively. The best arrangement of baffles is given and it is a reference for tunnel protective design and study.

Study on Composites for Furniture with Waste Paper and Wood Particle

The manufacturing process of particle composite for furniture, made of waste paper and wood particle, was studied and discussed in this paper, and an ornament cabinet and a Chinese style teapoy were assembled in the laboratory with the composite. The results showed the mechanical properties of composite made of waste paper, was low. Wood particle was blended with waste paper and made into composite, and the mechanical properties of the composite could meet the demand of particle board for furniture and ornament under the Chinese national standard. The application of waste paper-based composite was feasible technically.

Analysis of Soil-Structure Interaction (SSI) Effects on Seismic Response of Base-Isolated Structures

A new modified model for assessing the effects of SSI on base-isolated structures is presented from the case of conventional structures. The equations of motion of the equivalent fixed-base 2-DOF system are formulated in frequency domain. Based on this, rigorous and closed-form formulations for fundamental period and composite damping are derived. Finally, analysis of parameters based on frequency independent coefficients in detail is conducted. The analytical model and method presented can serve to assess the effects of SSI in the design of base-isolated structures including high-rise structures. Significant differences between the system with and without radiation damping and the flexibility of supporting soil have been observed in this study. For the results of the analysis, overall SSI effects have been identified as elongation of fundamental period of the system and decreased composite damping, especially for the high-rise and slender isolated structures.

Experimental Study on Bending Creep Behavior of Modified Fast-Grown Poplar Wood in Uncontrolled Condition

Three material properties (density, modulus of elasticity, bending creep deflection) of poplar wood modified with low molecular resin was examined and evaluated by an experimental approach. Poplar specimens were treated to achieve full penetration using a vacuum schedule with different low molecular resins. These resins were urea-formaldehyde (UF) and phenol-formaldehyde (PF) prepolymer solution. Creep tests were conducted under a varying climate with 16 °C ~ 31 °C and 40 % ~ 80 % relative humidity. The specimens were loaded in bending for approximately 140 days. Then the curves of the creep tests were analyzed to derive the development of bending creep performance. The results show modification leads to significant changes on material properties. Modification increases both the density and elastic modulus, and also tends to deflect creep deformation obviously less than untreated specimens.

Temperature Field in Simply Supported Laminated Beam

According to the two-dimensional thermal theory, the temperature distribution in a simply supported laminated beam is studied. Firstly, the temperature distribution in a single-layer simply supported beam is analytically derived. Then, based on the continuity condition of the temperature and heat flux between the connected layers, the temperature and heat flux relations between the lowest layer and the top layer of the beam are recurrently obtained. Finally, the unknown coefficients are determined by the upper and lower surface conditions of the laminated beam. The temperature in the beam is given by substituting the unknown coefficients back to the recurrent formulae.

Non-Linear Finite Element Analysis on Composite Shear Wall with Opening

A new composite structure system is proposed in this paper to suit the demand of building energy conservation and heat preservation. Based on the low reversed cyclic loading test, the non-linear finite element (FEM) analysis model of composite shear wall is established by ANSYS so as to study crack status, stress variation characteristics and failure process under the action of horizontal loading. The results of ANSYS finite element analysis show good agreement with the test results.

Engineering Application of Glued Laminated Timber Structures in China

An overall outline is given for the development of the glued laminated timber structures in China. Different types of glulam structures built in recent years, such as gymnasium, bridges, public buildings, traditional architecture, landscape structures have been discussed. During the development of glulam structure in the future, raising design and produce level will be the most important question we confront and should be settled.

Study on Lumped-Parameter Model of Surface Circular Foundation

This paper puts attention on the application of Chebyshev complex polynomials in the development of lumped-parameter model of surface circular foundation. The present method is an important extension to the concept of polynomial-fraction approximation in the foundation modeling. In the present analysis, the normalized flexibility function is adopted to improve the accuracy of the model and to reduce the parameters in modeling. The accuracy and validity of the lumped-parameter model is extensively investigated for the case of surface circular foundation. The proposed method may be easily applied to analyze various practical problems in soil-structure interaction such as vibration of machines on foundation and response of structures under earthquake.

Response of Liquid in Cylindrical Tank with Rigid Annual Baffle Considering Damping Effect

Sloshing response of liquid in a rigid cylindrical tank with a rigid annual baffle under horizontal sinusoidal loads was studied. The effect of the damping was considered in the analysis. Natural frequencies and modes of the system have been calculated by using the Sub-domain method. The total potential function under horizontal loads is assumed to be the sum of the tank potential function and the liquid perturbed function. The expression of the liquid perturbed function is obtained by introducing the generalized coordinates. Substituting potential functions into the free surface wave conditions, the dynamic response equations including the damping effect are established. The damping ratio is calculated by Maleki method. The liquid potential are obtained by solving the dynamic response equations of the system.