A novel predictor–corrector explicit integration scheme for structural dynamics

Structures ◽  
2021 ◽  
Vol 34 ◽  
pp. 2735-2745
Author(s):  
Wei Liu ◽  
Wenhua Guo
Keyword(s):  
Structural Dynamics ◽  
Integration Scheme ◽  
Explicit Integration ◽  
Predictor Corrector

Asymmetric FPSO Roll Response due to the Influence of Lines Arrangement

2012 ◽  
Author(s):  
Marcos Donato Ferreira ◽  
Mauro Costa de Oliveira ◽  
Rafaella Cristina Carvalho ◽  
Sergio Hamilton Sphaier
Keyword(s):  
Integration Scheme ◽  
Impulse Response Functions ◽  
Viscous Effects ◽  
Lumped Mass ◽  
Explicit Integration ◽  
Deep Waters ◽  
Campos Basin ◽  
Motion Responses ◽  
Non Linear ◽  
Ship Hydrodynamic

In the development of the mooring design of FPSOs in spread mooring system (SMS) configuration, it was observed that the utilization of asymmetric riser arrangement in deep waters might lead to an asymmetrical roll response of the FPSO. In particular, concentrating all riser connections on the portside, it could be observed that roll and heave coupling under the influence of the riser dynamics might lead to a much lower roll response associated with waves coming from portside than from the starboard direction. Simulations were carried using an in-house time domain simulator, where the ship hydrodynamic behavior was represented through the use of impulse response functions and the lines dynamic through the use of non-linear finite element method, using an explicit integration scheme and a lumped mass approach. Non-linear viscous effects could be easily associated to the ship and line velocities. Measured motion responses of an actual FPSO in operation in Campos Basin are compared with the computations.

The Anchor-Last Deployment Problem for Inextensible Mooring Lines

1975 ◽  
Vol 97 (3) ◽  
pp. 1046-1052 ◽  
Author(s):  
Robert C. Rupe ◽  
Robert W. Thresher
Keyword(s):  
Numerical Model ◽  
Equations Of Motion ◽  
Simultaneous Equations ◽  
Mooring Line ◽  
Integration Scheme ◽  
Lumped Mass ◽  
Mooring Lines ◽  
Concentrated Masses ◽  
Predictor Corrector ◽  
Lagrange’S Method

A lumped mass numerical model was developed which predicts the dynamic response of an inextensible mooring line during anchor-last deployment. The mooring line was modeled as a series of concentrated masses connected by massless inextensible links. A set of angles was used for displacement coordinates, and Lagrange’s Method was used to derive the equations of motion. The resulting formulation exhibited inertia coupling, which, for the predictor-corrector integration scheme used, required the solution of a set of linear simultaneous equations to determine the acceleration of each lumped mass. For the selected cases studied the results show that the maximum tension in the cable during deployment will not exceed twice the weight of the cable and anchor in water.

3D Elastic Deformable Object Model for Robot Manipulation Purposes

2014 ◽  
Vol 18 (3) ◽  
pp. 375-382 ◽  
Author(s):  
Khairul Salleh Mohamed Sahari ◽  
◽  
Yew Cheong Hou
Keyword(s):  
The State ◽  
Service Robots ◽  
Robotic Arm ◽  
Service Robot ◽  
Integration Scheme ◽  
Explicit Integration ◽  
Robot Manipulation ◽  
Deformable Object ◽  
Home Service ◽  
Mass Spring

This paper presents a mass-spring model applied to the manipulation of an elastic deformable object for home service robot application. A system is also proposed that is used to fold a piece of rectangular cloth from a specific initial condition using a robot. The cloth is modeled as a three-dimensional object in a two-dimensional quadrangular mesh based on a massspring system, and its state is estimated using an explicit integration scheme that computes the particle position as a function of the internal and external forces acting on the elastic deformable object. The current state of the elastic deformable object under robot manipulation is tracked based on the trajectory of the mass points in the mass-spring system model in a self-developed simulator, which integrates a massspring model and a five-degree-of-freedom articulated robotic arm. To test the reliability of the model, the simulator is used to predict the best possible paths for using the robotic arm to fold a rectangular cloth into two. In the test, the state of the object is derived from the model and then compared with the results of a practical experiment. Based on the test, the error is found to be generally acceptable. Thus, this model can be used as an estimator for the vision-based tracking of the state of an elastic deformable object for manipulation by home service robots.

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