| 1. |
- Eich, Edda, et al.
(författare)
-
On the error control for multistep methods applied to ODEs with invariants and DAEs in multibody dynamics
- 1995
-
Ingår i: Mechanics of Structures and Machines. - : Informa UK Limited. - 0890-5452. ; 23:2, s. 159-180
-
Tidskriftsartikel (refereegranskat)abstract
- A modified local error model is developed for numerical integration of ODEs with invariants. The basic idea is to use a commutativity relationship that holds for implicit state-space form methods. A new implicit state-space form predictor is developed from which error estimates can be obtained by predictor-corrector difference: This technique is demonstrated through the preliminary examples in this paper.
|
|
| 2. |
- Lundvall, Olle, et al.
(författare)
-
Prediction of transmission error in spur gears as a consequence of wear
- 2001
-
Ingår i: Mechanics of structures and machines (Print). - 0890-5452 .- 1525-612X. ; 29:4, s. 431-449
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of this article is to investigate how the so-called transmission error in a gear develops in a wear process. A finite element procedure for calculating wear between two elastic bodies in contact is developed that includes constitutive laws, representing the behavior of the interacting surfaces. When treating a gear problem, large rotations must be included. This is done by analyzing a sequence of finite-element models along with an interpolation procedure. The constitutive laws of interacting surfaces are Signorini's contact law, Coulomb's law of friction, and Archard's law of wear. By formulating both Signorini's contact law and Coulomb's law of friction by means of projection equations, the complete formulation of a time increment of a quasistatic wear-friction evolution problem becomes a system of nonsmooth equations. Then, a modified Newton method is applied to solve this system. The transmission error can be found from the infinitesimal displacement field superposed on the rigid body configuration. Results from the simulations show that wear will increase the peak-to-peak value of the transmission error. This is most significant in a gear when some kind of modification of the gear flank is applied to minimize the transmission error in an initial state.
|
|
| 3. |
- Lundvall, Olle, et al.
(författare)
-
Simulation of wear by use of a nonsmooth Newton method : a spur gear application
- 2001
-
Ingår i: Mechanics of structures and machines (Print). - 0890-5452 .- 1525-612X. ; 29:2, s. 223-238
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents a method for calculating wear between two elastic bodies in contact. Discrete representations of the bodies are obtained by the finite element method. Constitutive laws representing the behavior of the interacting surfaces are then added. These are Signorini's contact law, Coulomb's law of friction, and Archard's law of wear. By formulating Signorini's contact law and Coulomb's law of friction by means of projection equations, the complete formulation of a time increment of a quasistatic wear-friction evolution problem becomes a system of nonsmooth equations. A modification of Newton's method is applied to solve this system. The method is applied to a spur gear problem in a heavy truck transmission.
|
|
| 4. |
- Schaller, Christian, et al.
(författare)
-
Simulation of Multibody Systems by a Parallel Extrapolation Method
- 1994
-
Ingår i: Mechanics Based Design of Structures and Machines. - : Informa UK Limited. - 1539-7734. ; 22:4, s. 473-486
-
Tidskriftsartikel (refereegranskat)abstract
- In the simulation of multibody systems, the equations of motion are generated by so-called multibody formalisms as a system of differential-algebraic equations (DAEs). A recently developed extrapolation method for integrating the equations of motion is investigated. Extrapolation methods for ordinary differential equations are briefly reviewed, before proceeding to the DAE method. The inherent parallelism of the extrapolation scheme is used for an implementation on a transputer network. Implementation aspects such as the distribution of work during integration, and differences in stepsize control of serial and parallel algorithms are discussed. The efficiency of the parallel algorithm is demonstrated for a multibody system that is part of a mechanical printing device.
|
|
