The finite element modeling of the dynamic and wave problems in unbounded media requires an artificial boundary condition to simulate truncated infinite domain. Dirichlet-to-Neumann has been transformed from frequency time domain by using rational function approximation auxiliary variable technique. It is extended three-dimensional layer problem here. resulting stable itself domain, whereas time-domain instability coupled with method found for foundation vibration recently propagation A...

The Winkler foundation modulus is key to evaluating the response of underground structures using elastic beam model. In this paper, an improved formula for a embedded in full space proposed overcome limitation inconsistent assumptions previous studies. To achieve goal, bending responses are obtained model and three-dimensional continuum model, respectively, wherein consistent assumption that tangential interactions at beam–ground interface ignored two models. addition, as deformation site...

Purpose The purpose of this paper is to propose a new explicit time integration algorithm for solution the linear and non-linear finite element equations structural dynamic wave propagation problems. Design/methodology/approach completely so that no equation system requires solving, if mass matrix diagonal whether damping does or not. single-step method has simple starting applicable analysis with variable step size. second-order accurate conditionally stable. Its numerical stability,...

Abstract An accurate absorbing boundary condition (ABC) is developed in frequency domain for finite element analysis of scalar wave propagation unbounded layered half‐space. The proposed ABC H‐shaped line that consists two parts: a new at horizontal bottom to replace semiinfinite strip below and between vertical boundaries, general consistent lateral half‐space outside boundary. key point constructing the continued fraction (CF) presented expand dynamic stiffness underlying half‐space,...

In this paper, the interactions between double cracks with a co-bisector-line were investigated theoretically and experimentally. Fatigue crack growth tests of specimens single or carried out to measure rates, finite element calculations performed obtain stress intensity factors at tips. It was found that when are in co-bisector-line, they present shielding which reduce tips as well rates. By modifying Paris equation considering interactions, new simplification method proposed simplify into same

An analytical solution for the seismic‐induced thrust and moment of circular tunnel in half‐space under obliquely incident P waves is developed this study, which superposition deep tunnels reflected SV waves. To consider tangential contact stiffness at ground‐tunnel interface, a spring‐type coefficient introduced into force‐displacement relationship. Moreover, lining treated as thick‐wall cylinder, providing more precise forecasts than beam or shell models used previous solution, especially...

Cracks in engineered pipelines often appear the form of multiple cracks or crack clusters with interactions between them. It is important to study interaction if pipeline cluster be evaluated terms equivalence and safety assessment. In this paper, based on FRANC3D analysis software, circumferential parallel double inner surface was investigated, factors affecting were examined, empirical equations for calculating stress intensity factor (SIF) proposed. The results show that there no bias...

In the current vehicle-bridge dynamics research studies, displacement impact coefficients are often used to replace moment and shear force coefficients, vehicle model is also simplified as a moving-load without considering contribution of stiffness damping system in some concerned which cannot really reflect mechanical behavior structures under dynamic loads. This paper presents coupling for prediction responses coefficient long-span curved bending beam bridge. The element matrix mass box...

Purpose The purpose of this paper is to propose a stable high-order absorbing boundary condition (ABC) based on new continued fraction for scalar wave propagation in 2D and 3D unbounded layers. Design/methodology/approach ABC obtained (CF) expansion the frequency-domain dynamic stiffness coefficient (DtN kernel) artificial truncated infinite domain. CF which has been used thin layer method [69] will be applied DtN develop time-domain transient 2D. Furthermore, composite-CF proposed study...

Concrete is one of the most widely used engineering materials in field civil engineering. With extensive use concrete structures, people have paid more and attention to durability structures. Nowadays, research on structures has become a hotspot academics.The purpose this article study influence nanomaterials physical mechanics composite bridge piers, prepare nano-concrete by mixing appropriate number (nanoSiO2, liquid nanoSiO2 nanoFe2O3) into piers. The under combined action CO2 erosion...