This chapter introduces the finite element method (FEM) as a tool for solution of classical electromagnetic problems. Although we discuss the main points in the application of the finite element method to electromagnetic design, including formulation and implementation, those who seek deeper understanding of the finite element method should consult some of the works listed in the bibliography section.

Introduction to the Finite Element Method

Epoxy resins have been used as structural materials since the late 1940s. Despite their desirable properties such as high strength, excellent creep resistance, and good adhesion, they suffer from low fracture energy. Rubber modification as a major toughening approach to overcome the inherent brittleness of epoxy polymers was introduced during the early 1970s. Since then, a large number of investigations have been conducted to elucidate different aspects of rubber-toughened epoxies. The present work is a critical review of the field focusing on the important parameters affecting rubber-toughening. The studies reviewed are classified in five categories including roles of matrix ductility, rubber concentration, blend morphology, particle cavitation, and particle/matrix interface. It has been tried to provide an in-depth view of the state-of-the-art knowledge in the field and to direct future studies towards exploring new approaches for toughening of epoxy polymers.

Rubber-Toughened Epoxies: A Critical Review

This paper examines the potential effectiveness of the following three precollision system (PCS) algorithms: 1) forward collision warning only; 2) forward collision warning and precrash brake assist; and 3) forward collision warning, precrash brake assist, and autonomous precrash brake. Real-world rear-end crashes were extracted from a nationally representative sample of collisions in the United States. A sample of 1396 collisions, corresponding to 1.1 million crashes, were computationally simulated as if they occurred, with the driver operating a precollision-system-equipped vehicle. A probability-based framework was developed to account for the variable driver reaction to the warning system. As more components were added to the algorithms, greater benefits were realized. The results indicate that the exemplar PCS investigated in this paper could reduce the severity (i.e., ΔV) of the collision between 14% and 34%. The number of moderately to fatally injured drivers who wore their seat belts could have been reduced by 29% to 50%. These collision-mitigating algorithms could have prevented 3.2% to 7.7% of rear-end collisions. This paper shows the dramatic reductions in serious and fatal injuries that a PCS, which is one of the first intelligent vehicle technologies to be deployed in production cars, can bring to highway safety when available throughout the fleet. This paper also presents the framework of an innovative safety benefits methodology that, when adapted to other emerging active safety technologies, can be employed to estimate potential reductions in the frequency and severity of highway crashes.

Safety Benefits of Forward Collision Warning, Brake Assist, and Autonomous Braking Systems in Rear-End Collisions

Initiation of shear bands near a stress concentration in metallic glass

Problem statement: This study reviewed the needs of different constitutive models for rubber like material undergone large elastic deformation The constitutive models are widely used in Finite Element Analysis (FEA) packages for rubber components Most of the starting point for modeling of various kinds of elastomer is a strain energy function In order to define the hyperelastic material behavior, stress-strain response is required to determine material parameters in the strain energy potential and also proper selection of rubber elastic material model is the first attention Conclusion: This review provided a sound basis decision to engineers and manufactures to choose the right model from several constitutive models based on strain energy potential for incompressible and isotropic materials

A review of constitutive models for rubber-like materials

A new yield function and a hydrostatic stress-controlled void nucleation model for porous solids with pressure-sensitive matrices

A study on the material properties and fatigue life of natural rubber with different carbon blacks

A macroscopic constitutive law for porous solids with pressure-sensitive matrices and its implications to plastic flow localization

Driver inattention causes the majority of vehicular crashes, and these accidents produce extensive economic and social costs, as well as injuries and fatalities. Thus, the development of imminent crash detection systems is one of the most important issues in automotive safety. Various crash detection algorithms have been proposed, but the coverage of these algorithms has been limited to one or two crash scenarios. To widen the coverage of crash detection systems to include various crash modes, driver behaviors that are dependent on road scenes and vehicle dynamics should be considered. This paper proposed an algorithm for detecting an imminent collision in general road scenes. The proposed algorithm consists of crash probability data generated from Monte Carlo simulations that consider driver behavior and vehicle dynamics, a tracking algorithm that uses an interactive multiple-model particle filter, and a threat assessment algorithm that estimates crash probabilities. To reduce nuisance and false-positive alarms, the algorithm discriminated between normal and dangerous road scenes, and a point of no return was detected using three driver models that addressed different levels of driver input. The performance of the proposed algorithm was evaluated under three scenarios, and it successfully discriminated between collision and near-miss cases, and it adjusted warning times depending on the road scenes. It is expected that the proposed algorithm would have good driver acceptability based on the results of the near-miss cases. The proposed algorithm can be used as an integrated crash detection algorithm for crash warning, avoidance, and mitigation purposes while incorporating tracking information from multiple sources.

Hyun-Yong Jeong

Papers

A new yield function and a hydrostatic stress-controlled void nucleation model for porous solids with pressure-sensitive matrices

A study on the material properties and fatigue life of natural rubber with different carbon blacks

A macroscopic constitutive law for porous solids with pressure-sensitive matrices and its implications to plastic flow localization

A Novel Algorithm for Crash Detection Under General Road Scenes Using Crash Probabilities and an Interactive Multiple Model Particle Filter

Fatigue life prediction of solder joints with consideration of frequency, temperature and cracking energy density