汇报人：Joseph Lai；澳大利亚新南威尔士大学教授，

He was elected a Fellow of the Institution of Engineers Australia in 1993. He is a Fellow of the Australian Acoustical Society and an Associate Fellow of the American Institute of Aeronautics and Astronautics.

讲座一题目：From Flapping Wing Flight to Green Energy（从扑翼飞行器到绿色能源）

会议时间：2018年4月10日 15:00-17:00

会议地点：教一楼南第五会议室

Flight in nature has long inspired human aviation. With the rapid increase in the worldwide use of energy coupled with the depletion of fossil fuel resources and the need to significantly reduce greenhouse gas emissions, the development of means to extract energy from renewable sources has seen unprecedented attention and urgency. This talk will give an overview of our research into the aerodynamics of insect flight and how it can be exploited to harvest wind and hydro energy.

会议时间：2018年4月11日 15:00-17:00

会议地点：教一楼南第五会议室

讲座二题目：Termites thrive by using vibrations （白蚁通过振动的繁衍）

Termites are notoriously cryptic: infestations in houses are often discovered when an apparently intact timber object collapses, the archetypal ‘falling through the floor boards’. This behaviour is adaptive because remaining undiscovered is the termite’s primary defence against predators. However, being cryptic severely limits the ability of termites to explore their environment and assess potential food sources. Despite being blind and hidden, termites can assess a piece of wood swiftly after contacting only a small part of it (sometimes as little as a few square millimeters). Although termite soldiers have been known to produce vibratory alarm signals to warn conspecific workers, it is not until our sustained research over the last 10 years that termites have been shown to use vibrations as a principal tool for communications, making foraging decisions and detection. In this talk, some of our recent discoveries on the use of vibrations by termites will be discussed. These include their ability to determine food size and food quality, to distinguish loaded wood from unloaded wood, to eavesdrop to discriminate against competitors, and to detect and avoid predators.

讲座三题目：Challenges in the prediction of brake squeal propensity: nonlinearity and uncertainty （制动噪声预测的挑战：非线性和不确定性）

Despite significant progress made in the past 20 years in discovering some of the mechanisms of brake squeal, it remains difficult to predict the friction-induced instabilities reliably. Most numerical analyses are based on linear deterministic analyses of structural vibrations such as the complex eigenvalue analysis (CEA). However, nonlinear multi-scale processes govern friction contact with high sensitivities to operating and/or environmental conditions. In addition, uncertainties in the material properties and boundary conditions such as contact and friction laws are rarely considered. Hence, it is quite common to underpredict or overpredict the number of instabilities and extensive brake noise dynamometer tests are still required in industry to ensure acceptable brake noise performance. In this talk, the implications of nonlinearity and uncertainty for brake squeal predictions are discussed. The potential of these new insights for predicting brake squeal propensity with confidence is illustrated by their application to a full disc brake system.