Quantitative Multi-Physics Tools for Automotive Wiper Design

Abstract

<div class="section abstract"><div class="htmlview paragraph">The primary function of automotive windscreen wipers is to remove excess water and debris to secure a clear view for the driver. Their successful operation is imperative to vehicle occupants’ safety. To avoid reliance on experimental testing there is a need to develop physics-based models that can quantify the effects of design-based decisions on automotive wipers. This work presents a suite of evaluative tools that can provide quantitative data on the effects of design decisions. We analyse the complex non-linear contact interaction between the wiper blade and the automotive screen using finite element analysis, assessing the impact of blade geometry on the contact distribution. The influence of the evolution of normal applied load by the wiper arm is also investigated as to how it impacts the contact distribution evolution. The dynamics of the blade are subsequently analysed using a multiple connected mass spring damper system. Additionally, we apply hydrodynamic lubrication theory to study the residual film thickness post wipe and assess the effect of wiper blade geometry and lubricant composition. Finally, the complete wiper system is studied using a lump dynamic model, and bifurcation analysis is applied to determine areas of instability due to friction induced vibrations. Additionally, the wiper dynamics modelling shows peak frequencies occurring at 30-50Hz, which agrees well with a documented range of chatter frequencies. The friction coefficients calculated within the hydrodynamic model fall within experimentally documented ranges of lubricated sliding friction, <i>μ</i> ≈ 0.1. Furthermore, the areas of operational stability predicted by our bifurcation model coincide with current experimentally determined optimal operational regions for automotive wipers.</div></div>

Determining the characteristics of contact interaction between the two-row windshield wiper and a curvilinear glass surface

“…Our results of the distribution of pressure on stresses testify to the solution of the problem of studying the interaction of the windshield wiper with the curved surface of the glass. In contrast to [2][3][4][5][6][7][8][9][10], in which variants of the absolute repeatability of the curvature of the windshield wiper and the glass surface are considered, the current research data demonstrate the application of other possible cases of operation.…”

“…The reviewed literature [2][3][4][5][6][7][8][9][10][15][16][17][18][19][20][21][22][23] does not sufficiently describe other variants of rubber blades, except for the traditional single-row one. A variant of the rubber blade with an additional row of individual brushes located at an angle has shown useful practical results.…”

“…Works [2,3] do not contain studies of windshield wipers in critical operating conditions, which is one of the tasks of this work. Paper [4] delves into the complex non-linear interaction between the wiper blade and the vehicle glass using FEA, demonstrating how the shape of the brush affects the load distribution. Since the contact of the blade with the windshield depends on the movement of the windshield wiper, it is useful to refer to study [5], which focuses on the geometric synthesis of the mechanism of the front windshield wiper using rockers for fixing the brush.…”

“…Wiper mechanisms are also studied in [6]. Despite the relevance of the topics addressed in [4][5][6], the authors do not provide data on the resulting pressure on the glass surface from the side of the windshield wiper. In [7], the dynamic characteristics and mechanism of generating vibrations of a frameless windshield wiper are studied.…”