The hood closing characteristic in gas strut condition is different than in the stay rod condition. In stay rod condition, the hood closes once it is dropped from a minimum closing height and opening the hood requires effort. The gas strut in turn aids in hood opening but for hood closing it requires effort. In sports utility vehicles, due to bigger sizes of hood and architectural requirements dual latches and gas strut are employed on hood. In this condition, the hood can be closed either by dynamic single stroke or by quasi static two stroke conditions. In dynamic case, the hood is closed at higher velocity whereas in quasi static case force is applied first for secondary latching position and then for primary latching position. In this study, both the dynamic and quasi static closing conditions are compared in terms of closing force and velocity and hood over travel.
To ensure adequate visibility without creating excessive glare, vehicle headlights are designed to use a specific source of illumination. The optical designs of headlights gather the luminous flux produced by the light source to produce a useful beam pattern that meets the relevant requirements and standards for vehicle forward lighting. With the advent of solid state, light emitting diode sources for general illumination, an increasing number of LED replacement headlight bulb products has emerged over the past decade. In most cases, these LED replacement bulbs are not permitted for legal use on public roadways, but some countries have begun to permit specific LED replacement bulbs to be used legally on the road for specific makes, models and production years of certain vehicles. If they can be demonstrated to produce a beam pattern that meets the photometric requirements for a legal headlight, they are permitted to be used legally for on-road use.
A crucial component utilized in the trunk space is the luggage board. Positioned at the bottom of the trunk, the luggage board separates the vehicle body from the interior and provides support for luggage.The luggage board serves multiple functions, including load-bearing stiffness for luggage, partition structure functionality, noise insulation, and thermal insulation. To meet the increasing demand for luggage boards in response to the changing market environment, there is a need for a competitive new luggage board manufacturing method. To address this, the "integrated sandwich molding method" is required. The integrated sandwich molding method utilizes three key methodologies: grouping processes to integrate similar functions, analyzing materials to replace them with suitable alternatives, and overcoming any lacking functionality through integrated design structures.
Side doors are pivotal components of any vehicle, not only for their aesthetic and safety aspects but also due to their direct interaction with customers. Therefore, ensuring good structural performance of side doors is crucial, especially under various loading conditions during vehicle use. Among the vital performance criteria for door design, torsional stiffness plays an important role in ensuring an adequate life cycle. This paper focuses on investigating the impact of several door structural parameters on the torsional stiffness of side doors. These parameters include the positioning of the latch, the number of hinge mounting points on doors (single or double bolt), and the design of inner panel with or without Tailor Welded Blank (TWB) construction.
In the early stages of vehicle development, it is critical to establish performance goals for the major systems necessary for NVH. The fundamental modes of BIW and chassis frames are typically assessed using FE models, discretized using 3D shell elements. However, the use of the 3D shell-based FE method is problematic in terms of fast analysis and quick decision-making, especially during the concept phase of a vehicle design because it takes much time and effort for detailed modeling. To overcome these weaknesses, a 1D method based on beam elements has been extensively studied over several decades, but it was not successful because of low analysis accuracy for thin-walled beam structures. This investigation proposes a 1D method based on thin-walled beam theory for fast analysis of vehicle structures with comparable accuracy to 3D shell models.
The Time-Sensitive Networking (TSN) working group has introduced a comprehensive set of standards to enable reliable communication in time-critical systems. The TSN standards set encompasses several shaping mechanisms that aim to provide bounded transmission latency for streams in the network. Among these shaping mechanisms, Cyclic Queuing and Forwarding (CQF) and frame preemption provide deterministic guarantees for frame transmission. However, despite some current studies on the performance analysis of CQF and frame preemption, they also need to consider the potential effects of their combined usage on frame transmission. Furthermore, there is a need for more research that addresses the impact of parameter configuration on frame transmission under different situations and shaping mechanisms, especially in the case of mechanism combination.
In the process of designing the aerodynamic kit for FSAE racing cars, there is a lot of repetitive work and low efficiency in optimizing parameters such as the angle of attack, chord length, and wing gap size. The optimization of these parameters is difficult to achieve through theoretical analysis and heavily relies on simulation results and design experience. Due to the short design cycle of racing cars, it is challenging to achieve the optimal solution. By establishing a parametric model in CAD software and integrating it with CFD software, the model parameters are automatically modified, imported into the CFD software for automatic simulation, and the simulation results are automatically analyzed using statistical methods. Based on the results, the model parameters are optimized within the allowable range of rules. After multiple iterations, the parameters are fully automatically optimized, achieving a higher negative lift coefficient.
ADAS (Advanced Driver Assistance Systems) is a growing technology in automotive industry, intended to provide safety and comfort to the passengers with the help of variety of sensors like radar, camera, LIDAR etc. Though ADAS improved safety of passengers comparing to conventional non-ADAS vehicles, still it has some grey areas for safety enhancement and easy assistance to drivers. LCDAS (Lane Change Decision Aid Systems) is a ADAS function which assists the driver while lane changing. LCDAS consists of two sub functions BSW (Blind Spot Warning) and LCA (Lane Change Assist). BSW alerts the driver about the vehicles which is in blind zone in adjacent lanes and LCA alerts the driver about approaching vehicles at a high velocity in adjacent lanes. In current, BSW and LCA systems alerts are given as optical and acoustic warnings which is placed in vehicle side mirrors. So, the driver has to see the side mirrors to take a decision while changing the lane.
The need for accuracy in element design and manufacturing is greater now than ever before in engineering industries. In order to increase accuracy, the part design and function must be clearly communicated between the design engineer and the manufacturing technicians, especially in automotive industry and feeder industries. Geometric Dimensions and Tolerances (GD&T) is an engineering symbolic language that clearly discusses a part function, priority and quality. The GD&T system of elements determines the quality, importance and price of the designed product. The standard used in the United States to define GD&T methodology is ASME Y14.5-2009 while the standard used in Europe is ISO 1101-2017. This article discussed the importance of using GD&T system including the types of geometrical features, limitations and accuracy, feature control frame, datum references frame to handle these symbols seamlessly.
Automotive body structures are being increasingly made in multi-material system consisting of steel, aluminum (Al) and fiber-reinforced plastics (FRP). Therefore, many joining tech-niques such as self-piercing riveting (SPR) and adhesive bonding have been developed. On the other hand, OEMs want to minimize the number of joining techniques to reduce the manufacturing complexity. Amount all joining methods, resistance Spot welding (RSW) is the most advanced and cost-effective one for body-in-white. However, RSW cannot be applied for joining dissimilar materials. Therefore, a novel Rivet Resistance Spot Welding method (RRSW) was developed in which Al or FRP Components can be directly welded to steel structures with existing welding systems. RRSW uses rivet-like steel elements as a welding adapter which are formed into Al or FRP components dur-ing their forming process. After that, they are welded to the steel components by RSW. This paper shows at first the results on Steel – Al RRSW.
In vehicle development, reducing noise is a major concern to ensure passenger comfort. As electric vehicles become more common and engine and vibration noises improve, the aerodynamic noise generated around the vehicle becomes relatively more noticeable. In particular, the fluctuating wind noise, which is affected by turbulence in the atmosphere, gusts of wind, and wake caused by the vehicle in front, can make passengers feel uncomfortable. However, the cause of the fluctuating wind noise has not been fully understood, and a solution has not yet been found. The reason for this is that fluctuating wind noise cannot be quantitatively evaluated using common noise evaluation methods such as FFT and STFT. In addition, previous studies have relied on road tests, which do not provide reproducible conditions due to changing atmospheric conditions. To address this issue, automobile manufacturers are developing devices to generate turbulence in wind tunnels.
This paper analyzes the mechanism of vibrational energy propagation and panel vibration generation at the point joints between frame and panel which can be applied to reduce the vehicle interior noise. In this study, we focused on the traveling wave in the early stage of propagation before the mode is formed, and investigated the mechanism of panel vibration generation due to wave energy propagation and its reduction method. First, we show theoretically that the out-of-plane component of the transmitted power at the point junction between frame and panel that contributes to panel vibration is associated with frame deformation. Then, we show through numerical verification that panel vibration can be reduced by reducing the transferred power of the out-of-plane component, and explain the effectiveness of the frame-to-panel joint design guidelines based on energy propagation analysis. Next, This analysis technique is applied to the vehicle body model.
The coordinated emission reduction management strategy of the P2.5 hybrid system is based on the engine torque management, engine speed management, the catalyst heat time control and the motor torque control. For HEV models, in addition to the traditional engine body control method, the following unique methods for HEV models can also be used to control emissions. The main principle is to make the engine work as much as possible in steady state conditions or to control engine emissions by limiting the engine load. The system divides the catalyst heating stage into one stage and two stages. The first stage corresponds to the use of motor to drive the vehicle so that the engine is in idle idling condition. On the one hand, it can stabilize the heating catalyst, and on the other hand, it can avoid the air-fuel ratio shock caused by speed and load fluctuations, which leads to the deterioration of emissions.