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FEA based simulations are extensively used in automotive industry for improving the product design and reducing the time taken for design and prototyping. FEA based simulations require material data as an input in form of material models. Most commonly used material models for simulation of metallic materials are elastic models and elasto-plastic models, which provide very good correlation till ultimate tensile strength (UTS). For simulation beyond UTS value, elasto-plastic material model has to be used along with material model considering the damage accumulation post UTS. For crash like event in automotive crash, required material models should consider the effect of various stress state conditions (Triaxiality) and strain rate sensitivity of materials along with damage accumulation. In LS Dyna solver, MAT_ADD_EROSION material model (GISSMO) along with MAT_024 is widely used for these applications.

This paper aims at investigating the effect of strain ratio on LCF behavior of dual phase (DP) steel at room temperature. LCF tests are generally performed at strain ratio of -1. In real life scenarios, cyclic loading does not usually correspond to fully reversed condition due to operational circumstances such as preload, duty cycle, vibrations or the environmental effects. Therefore, it becomes necessary to investigate the fatigue properties and LCF behavior for un-symmetric loading conditions as well. Dual Phase (DP) steels are extensively used in automotive industries owing to its large energy absorption capacity in the event of crash. Hence, evaluation of their LCF behavior becomes crucial. In this study, tests are carried out under strain-controlled conditions at two different strain ratios (-1 and 0.1) to investigate the LCF and mean stress relaxation behavior of a DP steel.

Magnesium is sought to be one of the futuristic material in automotive due to its superior properties such as density, strength to weight ratio, damping characteristics and thus, making it a key enabler for light weighting. The properties of Magnesium alloys can be widely altered by change in elemental composition and heat treatment. Analysis of composition and phase morphology are driving factors for determining component’s end use properties and can be utilized effectively in its product development cycle. The as-cast AZ series alloys develop microstructure consisting of α-Mg matrix, eutectic α-Mg/γ-Mg17Al12 phase with non-uniform Al solute content in the α-Mg. Solutionising causes dissolution of Mg17Al12 brittle phase thereby increasing strength and ductility in these alloys. This paper presents analysis of AZ series automotive alloy components with focus on microstructure and mechanical properties change after solutionising.

Design of real time active controls for structural dynamics problems requires a very precise mathematical model, to closely determine the system dynamic behavior, under virtual simulation. The finite element models can somehow be used as a mathematical model but due to complex shape/structure of the component, the size of discrete models resulting from finite element analysis is usually very large, causing the virtual simulation to be extremely computationally intensive and time consuming, also the boundary conditions applied are not very scalable, making the system deviate from its real dynamic behavior. Thus, this paper deals with the design of a Model Order Reduction technique, using orthogonal decomposition of system matrices, which can be used for creating accurate low-order dynamic model with scalable boundary conditions.

Active control mainly comprises of three parts; sensor-detects the input disturbance, actuator -provide counter measures and control logic -processing of input disturbances and converting it into logical output. Lot of methods for active vibration control are available but this paper deals with active control of steering wheel vibrations of an LCV. A steering wheel is, one such component that directly transfers vibration to the driver. Active technique described here is implemented using accelerometer sensor, IMA (Inertial Mass Actuator) and feed forward Fx-LMS (Filtered reference Least Mean Square) control algorithm. IMA is a single-degree-of-freedom oscillator. To enable a control, IMA needs to be coupled to the structure at a single point, acting as an add-on to the passive system. Fx-LMS is a type of adaptive algorithm which is computationally simple and it also includes compensation for secondary path effects by using an estimate of the secondary path.

A vehicle's suspension system is the basic component which decides its dynamic performance. It is designed to separate the vehicle body and its passengers or payload from vibrations arising due to road disturbances, at the same time to ensure that the tires stay in adequate contact with the road surface. Challenges in suspension design many a time's leads in a compromise between the conflicting demands of ride comfort and road holding. Vehicles having soft suspension isolate the vehicle body from the higher frequencies in suspension but reduce the ability of the dampers to control the wheel movements which leads to poor road holding. Conversely, hard suspension provides more road holding but transmits more of the suspension movement to the body; in turn provide a less comfortable ride. The development of active/ semi active suspension has addressed both these needs and provides optimum level of ride comfort and road holding which results in the safety and driving pleasure.