The paper deals with the design and manufacturing of a McPherson suspension arm made from short glass fiber reinforced polyamide (PA66). The design of the arm and the design of the molds have been made jointly. According to Industry 4.0 paradigms, a full digitalization of both the product and process has been performed.Since the mechanical behavior of the suspension arm strongly depends on constraints which are difficult to be modelled, a simpler structure with well-defined mechanical constraints has been developed. By means of such simple structure, the model for the behavior of the material has been validated. Since the suspension arm is a hybrid structure, the associated simple structure is hybrid as well, featuring a metal sheet with over-molded polymer. The issues referring to material flow, material to material contact, weld lines, fatigue strength, high and low temperature behavior, creep, dynamic strength have been investigated on the simple structure. The detailed understanding gained with the simple structure has been transferred on the actual suspension arm.The McPherson arm has been produced and withstood the technical specifications.

With the increasing frequency of fire incidents of electric vehicles, the safety of power batteries has attracted more and more attention. At present, the research on the safety of power batteries is mainly focused on fresh batteries. As the state of health of batteries deepens, how the safety of the battery evolves is not clear enough so far. This paper analyzes the external short-circuit safety of a NCM/C rectangular battery under different state of charges. The results show that when the cycle number is less than 800, the maximum temperature of the battery during short-circuit is below 130 °C. The main failure mode of the battery is bulging in volume or opening of the explosion-proof valve and there is no obvious regularity between the failure mode with the cycle life. However, when the cycle number reaches 1000, the battery goes into thermal runaway during the safety test. In specific, the explosion-proof valve opens, and a large amount of smoke is sprayed, and the surface temperature of the battery reaches 350 °C with obvious burn marks.…

By their nature as chaotic, high-energy events, rollovers pose an injury risk to occupants, in particular through exposure to perimeter contact and ejection. While seatbelts have long been accepted as a highly effective means of retaining occupants, it has been suggested that technologies such as laminated safety glazing or rollover curtain airbags could alternatively provide effective occupant containment during rollovers. In this study, a full-scale dolly rollover crash test was performed to assess the occupant containment capacity of laminated side glazing and rollover curtain airbags in a high-severity rollover. This allowed for the analysis of unrestrained occupant kinematics during interaction with laminated side glazing and rollover curtain airbags and evaluation of failure modes and limitations of laminated glazing and rollover curtain airbags as they relate to partial and complete ejection of unrestrained occupants. The dolly rollover was performed with a 2010 Chevrolet Express at a nominal speed of 43 mph, with unbelted anthropomorphic test devices (ATDs) positioned in the driver, right front passenger, and designated third, fourth, and fifth row seating positions. Vehicle dynamics and…

In the era of fierce competition, launching a defect free product on time would be the key to success. In a modern automobile, the transmission system is designed with utmost care in order to transfer the maximum power from engine to driveline smoothly and efficiently. Optimized design of all the transmission components is necessary in order to meet the power requirement with the least possible weight. This optimization may require gear designs with different internal diameters. The assembly of these gears may not be possible on a solid transmission shaft. To facilitate assembling while retaining optimum design of transmission parts, a separate bush is designed to overcome this limitation. Some bushes may require a flange to restrict any free play of the mounted gear in its axial direction. During complete system level testing of one newly developed manual transmission, bush failure was observed. Bushes are generally press fitted on the transmission shafts, on which the needle roller bearing is mounted. In some cases, the free axial movement of the gear is restricted by the hub…

Automotive Wheel Hub is a safety critical component. Integrated Wheel hub design is improved from 1st generation to 3rd generation to meet the durability targets with less weight. Lateral loading is critical parameter for designing wheel hub. Cornering test is performed at vehicle level to evaluate wheel hub. Cornering test has combination of three types of tracks. In Wheel hub design, flange radius and flange width are two important design parameters to meet the durability life for cornering loads. We have considered the combination of different flange radius and flange width to understand the effect of these two parameters on wheel hub fatigue life. These three-wheel hubs are tested till failure and life scatter is plotted. Strain data is acquired at flange radius on wheel hub for all cornering test tracks. Using Wheel Force Transducers (WFT), Forces and moments are acquired at wheel center for all cornering test tracks. Duty cycle is derived from measured loads. FE model of Wheel end simulation contains Wheel hub, Wheel rim, Knuckle, drive shaft and wheel nut. FE Analysis…

An examination of field-fractured windshields was conducted for the purpose of determining their principle fracture mechanisms experienced in-use. Parts for the study were gathered both in the United States (state of NY) and in Europe (France) to explore whether the primary causes of failure were similar or different for the different regions. In total, over two hundred individual field-fractures were obtained and examined for the study. Detailed fracture analysis of the parts was performed, and several different fracture mechanisms were identified and quantified. It was found that the two most dominant failure modes were common for both geographic regions. The most frequent cause (~70%) of windshield fracture was due to sharp particle impact of the exterior ply, while Hertzian cone cracking of the outer ply was the second leading cause (~20%). These and other observed failure modes are detailed below. Given that sharp impact fracture was the dominant failure mode observed, a new high-speed, sharp impact test method was developed and deployed to evaluate numerous laminate constructions for their resistance to this type of event.…

According to the increasing demands for light-weight design in the automotive industry, the use of thinner and lighter materials such as aluminum alloys for automotive parts has led to significant weight reduction. The joining of these materials has required development of new technologies in joining/fastening rather than welding. Flow drill screwing is one of the latest technologies created to fasten sheet metal panels.This paper discusses results of an evaluation of fatigue characteristics of flow drill screw (FDS) joints based on experimental data and observations from the literature. It was observed that the important fatigue-related geometric parameters of FDS joints were the gap between sheets and the extruded (or bulged) zone during screwing. Major failure modes were observed such as sheet failures where cracks grow from the inner surface of the sheet and around the extruded zone.In this paper, the fatigue evaluation procedure for FDS joints using the mesh-insensitive equilibrium-based structural stress (ESS) method was used. The ESS-based simplified modeling procedure was used for the fatigue-evaluation procedure for FDS joints. The effectiveness and applicability of the…

Today engine downsizing, weight reduction, boosting, etc. are widely used in modern combustion engine designs in order to increase power output, improve fuel economy, and reduce emission. However utilizing of these advanced technologies is making the engine less rigidity and resulting in potential fretting damages on any contact surfaces of engine components due to higher cyclic relative motions. The leakage failure of the cylinder-head sealing system induced by fretting damage on engine head and block deck surfaces is the one of major failure modes in the modern combustion engine. In this paper, the characteristics and failure modes of the MLS head gasket sealing system is introduced first. The fretting mechanism between MLS head gasket and engine head and block is then investigated and a fretting damage parameter and a damage criterion as well are defined and established to evaluate the crack nucleation or wear initiation. Also it is important to identify two types of loads during engine operation in the fretting damage calculation. The developed methodology is successfully verified through a good correlation between CAE…

This paper studied the process development of dissimilar clinch joints in cross-tension specimens of aluminum alloy 5052-H32 (AA5052-H32)/thermoplastic carbon fiber reinforced plastic (TP-CFRP) sheets. The AA5052-H32 and TP-CFRP sheets with a thickness of 1.6 mm were used. The important processing parameters for AA5052/TP-CFRP clinch joints, such as the punching load, heating mode, heating temperature, and die depth, were considered. The failure loads, failure modes, and metallographic micrographs of AA5052/TP-CFRP clinch joints were analyzed to determine an available processing parameter set for fatigue tests. Finally, the fatigue performance and failure mode of AA5052/TP-CFRP clinch joints were obtained.

Lithium-ion (or Li-ion) battery systems are being increasingly used as the main power source in new generation hybrid and electric vehicles. Their mechanical integrity under abuse loading conditions is very important for vehicle safety design. In this research, a computational study was performed to simulate mechanical tests on vehicle battery cells and modules. The tests were conducted on commercial Li-ion battery cells and entire modules at low speed using a high capacity material testing system. Based on loading and boundary conditions during the tests, finite element (FE) models using the explicit FEA solver LS-DYNA, were developed. The model predictions demonstrated reasonable agreement in terms of failure modes and force-displace response at both cell and module levels. With this newly developed numerical model for the entire battery module, a parametric study was performed to investigate the effect of small design modifications on its overall behavior subject to punch penetration.