TY - JOUR A1 - Schuderer, Matthias A1 - Rill, Georg A1 - Schaeffer, Thomas A1 - Schulz, Carsten T1 - Friction modeling from a practical point of view JF - Multibody System Dynamics N2 - AbstractRegularized static friction models have been used successfully for many years. However, they are unable to maintain static friction in detail. For this reason, dynamic friction models have been developed and published in the literature. However, commercial multibody simulation packages such as Adams, RecurDyn, and Simpack have developed their own specific stick-slip models instead of adopting one of the public domain approaches. This article introduces the fundamentals of these commercial models and their behavior from a practical point of view. The stick-slip models were applied to a simple test model and a more sophisticated model of a festoon cable system using their standard parameters. KW - Multibody dynamics KW - Friction KW - Stick-slip effect KW - Adams KW - RecurDyn KW - Simpack Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-72513 SN - 1384-5640 N1 - Corresponding author: Matthias Schuderer PB - Springernature ER - TY - JOUR A1 - Rill, Georg A1 - Schaeffer, Thomas A1 - Schuderer, Matthias T1 - LuGre or not LuGre JF - Multibody System Dynamics N2 - The LuGre model is widely used in the analysis and control of systems with friction. Recently, it has even been made available in the commercial multibody dynamics simulation software system Adams. However, the LuGre model exhibits well-known drawbacks like too low and force rate-dependent break-away forces, drift problems during sticking periods, and significant differences in non-stationary situations between the pre-defined friction law and the one produced by the LuGre model. In the present literature, these problems are supposed to come from the model dynamics or its nonlinear nature. However, most of these drawbacks are not simple side effects of a dynamic friction model but are caused in the LuGre approach, as shown here, by a too simple and inconsistent model of the bristle dynamics. Standard examples and a more practical application demonstrate that the LuGre model is not a “what you see is what you get” approach. A dynamic friction model with accurate bristle dynamics and consistent friction force is set up here. It provides insight into the physical basis of the LuGre model dynamics. However, it results in a nonlinear and implicit differential equation, whose solution will not be easy because of the ambiguity of the friction characteristics. The standard workaround, a static model based on simple regularized characteristics, produces reliable and generally satisfactory results but definitely cannot maintain a stick. The paper presents a second-order dynamic friction model, which may serve as an alternative. It can maintain a stick and produces realistic and reliable results. KW - Dynamic friction model KW - LuGre model KW - Asymmetric regularization KW - Break-away force KW - Stick-slip KW - Multibody dynamics Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-65653 N1 - Corresponding author: Georg Rill PB - Springer ER -