Mesoscopic scale simulation and wear investigation of self-lubricating fabric liner based on representative volume element

As the self-lubricating layer of self-lubricating spherical plain bearings, fabric liner shows obvious heterogeneous anisotropic characteristics, so it is a technical difficulty to predict its wear properties. In this paper, the continuous wear of self-lubricating fabric liner was simulated based on the mesoscopic scale wear model. The macroscopic wear properties of the fabric liner were characterized by establishing a representative volume element (RVE), and subsequently imposing periodic boundary restrictions (PBCs) on periodic surfaces. In order to avoid excessive mesh distortion, voxel grids meshing method was used, and then continuous wear of the heterogeneous material was realized by adjusting node coordinates and combining nodes. Detailed comparison between simulation prediction results and wear test data of fabric liner was made. The good correlation of the results confirmed that the mesoscopic scale wear model could be used in accurately predict the tribological performance of fabric composite.

Homogenization of fully nonlinear rod lattice structures: on the size of the RVE and micro structural instabilities

This work investigates the possibility of applying two-scale computational homogenization to rod lattice structures emerging, for instance, from additive manufacturing. The influence of the number of unit cells within the representative volume element (RVE), thus, the RVE’s size on the homogenized mechanical response is studied for occurring microscopic structural instabilities. Therein, the macro-scale, described in terms of three-dimensional continuum mechanics, is coupled to the micro-scale described by geometrically exact rods, enabling arbitrary large deformations and rotations. A special feature of the presented framework is that the rods building the lattice structures are not restricted to deform purely elastically but may deform inelastically. The mechanical response of lattice structures is investigated by applying the developed homogenization method to an exemplary lattice. Under special loads the structure reaches an instable state and may buckle. The appearance of instabilities depends on the geometric properties of the lattice’s underlying rods and the RVE’s size.