Stochast!c response of a tension leg platform to viscous and potential drift forces
نویسندگان
چکیده
The wave drift forces on tension leg platforms (TLP) are contributed by secondorder potential and viscous wave load effects, the fluctuations in wave surface elevation and the influence of platform displaced position on the wave excitation. These forces are expressed in terms of in phase and out of phase drift forces. In this study, computationally efficient time domain and frequency domain based schemes are developed to evaluate the TLP response to drift forces. These schemes retain the statistical relationship that exists among these drift forces and the first-order wave forces which is important for the combined response analysis. A parameter study is conducted to delineate the relative significance of different drift forces for several representative sea-states.
منابع مشابه
آنالیز هیدرودینامیکی سکوهای شناور با پایه های کششی
Among compliant offshore platforms, tension leg platforms (TLP) are referred to, as hybrid structures. This kind of platforms resemble to ordinary semi submersibles when their serge, sway and yaw motions are considered, since they are compliant whereas with respect to pith, roll and heave motions they respond more like a fixed platform rather than a floating body. This paper presents a method t...
متن کاملEFFICIENT NUMERICAL DYNAMIC ANALYSIS OF TENSION LEG PLATFORMS UNDER SEA WAVE LOADS
However it is possible to use of numerical methods such as beta-Newmark in order to investigate the structural response behavior of the dynamic systems under random sea wave loads but because of necessity to analysis the offshore systems for extensive time to fatigue study it is important to use of simple stable methods for numerical integration. The modified Euler method (MEM) is a simple nume...
متن کاملInfluence of Tether Length in the Response Behavior of Square Tension Leg Platform in Regular Waves
The tension leg platform (TLP) is a vertically moored structure with excess buoyancy. The TLP is regarded as moored structure in horizontal plan, while inherit stiffness of fixed platform in vertical plane. In this paper, a numerical study using modified Morison equation was carried out in the time domain to investigate the influence of nonlinearities due to hydrodynamic forces and the coupling...
متن کاملHydrodynamic damped pitch motion of tension leg platforms
Because of fluctuation in leg tension, pitch motion is very effective fatigue and life safety of leg elements in tension leg structures (TLSs). In this paper an exact solution for pitch vibration of a TLS interacting with ocean wave is presented. The legs of TLP are considered as elastic springs. The flow is assumed to be irrotational and single-valued velocity potentials are defined. The effec...
متن کاملSimple Pile-Soil Interaction Effect on Seismic Response of Fixed Offshore Platforms
In this paper effect of pile-soil consideration in obtaining seismic response offshore structure is assessed due to earthquake loading. InducedSeismic force is one of the most important excitations for the dynamic response of an offshore structure. According to API, Seismic forces should be accounted in platform design for seismically active regions in order to determine the allowable seismic r...
متن کامل