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Technical Paper

Human Perception of Seat Vibration Quality Pilot Study

2021-08-31
2021-01-1068
Driving comfort and automotive product quality are strongly associated with the vibration that is transmitted to the occupants of a vehicle at the points of contact to the human body, including the seat, steering wheel, and pedals. Of these three contact locations, the seats have the most general importance, as all occupants of a vehicle experience seat vibration. Particularly relevant to driving comfort is the way in which vehicle occupants perceive seat vibration, which may be different than expected considering sensor measured vibration levels. Much of the interest in seat vibration has been focused on internal combustion engine powertrain vibration, especially idle vibration. However, electrification of vehicles changes the focus from low frequency idle vibration to higher frequency vibration sources.
Technical Paper

Structural Analysis and Design Modification of Seat Rail Structures in Various Operating Conditions

2020-04-14
2020-01-1101
This paper is based on, and in continuation of the work previously published in ASEE NCS Conference held in Grand Rapids, MI [1]. Automotive seating rail structures are one of the key components in the automotive industry because they carry the entire weight of passenger and they hold the structure for seating foams and other assembled key components such as side airbag and seatbelt systems. The entire seating is supported firmly and attached to the bottom bodywork of the vehicle through the linkage assembly called the seat rails. Seat rails are adjustable in their longitudinal motion which plays an important role in giving the passengers enough leg room to make them feel comfortable. Therefore, seat rails under the various operating conditions, should be able to withstand the weight of the passenger along with the other assembled parts as mentioned above. Also, functional requirements such as crash safety is very important to avoid or to minimize injuries to the occupants.
Technical Paper

Characteristics of Trailer Rear Impact Guard - Interdependence of Guard Strength, Energy Absorption, Occupant Acceleration Forces and Passenger Compartment Intrusion

2008-04-14
2008-01-0155
FMVSS 223 and 224 set standards for “Rear Impact Protection” for trailers and semi-trailers with a gross weight rating greater than 10000 pounds. A limited amount of experimental data is available for evaluating the different performance attributes of rear impact guards. The crash tests are usually limited to fixed parameters such as impact speed, guard height, strength and energy absorption, etc. There also seems to be some misunderstanding of the interdependence of guard strength and energy absorption, and their combined effect on the guard's ability to limit underride while keeping occupant acceleration forces in a safe range. In this paper, we validated the Finite Element (FE) model of an existing rear impact guard against actual FMVSS 223 tests. We also modified a previously evaluated FE model of a 1990 Ford Taurus by updating its hood geometry and material properties.
Technical Paper

Design and Development of a Cylindrical HVAC Case

2004-03-08
2004-01-1385
There are many opportunities in a current automotive HVAC case for improved performance, and cost savings. Based on these opportunities, a new HVAC case design has been developed. This new design is smaller and lighter than current cases while meeting many of the performance requirements. The case also features a unique plenum design for air distribution to the three modes, panel, floor, and defrost. The results of simulation and laboratory testing confirmed the concept of the new HVAC design.
Technical Paper

A Parametric Computationally - Based Study of Windshield Heat Transfer Subject to Impinging Airflow

2004-03-08
2004-01-1382
Impinging jets are an established technique for obtaining high local heat transfer coefficients between a fluid and a surface. Factors such as jet attachment, surface angle, jet angle, separation distance between jet orifice and surface of impingement, and trajectory influence heat transfer dramatically. In the current study, the specific application of interest is air issuing from the defroster's nozzles of a vehicle and impinging on a glass windshield. The current work is aimed at studying the flow patterns off a vehicle windshield as a result of air issuing from various nozzle configurations. The effects of openings' geometry (circular vs rectangular), number of openings, angle that the windshield makes with the horizontal plane and angle of impinging jet, on windshield heat transfer is examined. An optimal configuration will be recommended for better heat transfer.
Technical Paper

High Speed Measurement of Contact Pressure and Area during Knee-to-Instrument Panel Impact Events Suffered from Frontal Crashes

2001-03-05
2001-01-0174
Numerous human cadaver impact studies have shown that acute injury to the knee, femoral shaft, and hip may be significantly reduced by increasing the contact area over the anterior surface of the knee. Such impact events are common in frontal crashes when the knee strikes the instrument panel (IP). The cadaveric studies show that the injury threshold of the knee-thigh-hip complex increases as the contact area over the knee is likewise increased. Unfortunately, no prior methodology exists to record the spatial and temporal contact pressure distributions in dummy (or cadaver) experiments. Previous efforts have been limited to the use of pressure sensitive film, which only yields a cumulative record of contact. These studies assumed that the cumulative pressure sensitive film image correlated with the peak load, although this has never been validated.
Technical Paper

Investigation of Airflow Induced Whistle Noise by HVAC Control Doors Utilizing a ‘V-Shape’ Rubber Seal

2011-05-17
2011-01-1615
Doors inside an automotive HVAC module are essential components to ensure occupant comfort by controlling the cabin temperature and directing the air flow. For temperature control, the function of a door is not only to close/block the airflow path via the door seal that presses against HVAC wall, but also control the amount of hot and cold airflow to maintain cabin temperature. To meet the stringent OEM sealing requirement while maintaining a cost-effective product, a “V-Shape” soft rubber seal is commonly used. However, in certain conditions when the door is in the position other than closed which creates a small gap, this “V-Shape” seal is susceptible to the generation of objectionable whistle noise for the vehicle passengers. This nuisance can easily reduce end-customer satisfaction to the overall HVAC performance.
Technical Paper

Application of a Knee Injury Criteria for the Hybrid III Dummy to Address a Variety of Car Crash and Restraint Scenarios

1999-03-01
1999-01-0710
Numerous studies have documented that lower extremity injury is second only to the head and face in automotive accidents. Such injuries are common because the lower extremity is typically the first point of contact between the occupant and the car interior. Of all lower extremity injuries, the knee is the most common site of trauma. This typically results from high speed contact with the instrument panel which can produce fracture and subfracture (contusions, lacerations, abrasions) level injuries. Current Federal safety guidelines use a bone fracture criterion which is based solely on a peak load. The criterion states that loads exceeding 10 kN will likely result in gross bone fracture. However, cadaver experiments have shown that increased contact area (via padding) over the knee can significantly increase the amount of load that can be tolerated before fracture or subfracture injury.
Technical Paper

The Effects of Retained Fluid and Humidity on the Evacuation of Critical Vehicle Systems

1999-05-10
1999-01-1630
In automotive assembly facilities worldwide, many critical vehicle systems such as brakes, power steering, radiator, and air conditioning require the appropriate fluid to function. In order to insure that these critical vehicle systems receive the correct amount of properly treated fluid, automotive manufacturers employ a method called Evacuation and Fill. Due to their closed-loop design, many critical vehicle systems must be first exposed to vacuum prior to being flooded with fluid. Only after the evacuation and fill process is complete will the critical vehicle system be able to perform as specified. It has long been thought, but never proven, that humidity and entrenched fluid were major hindrances to the Evacuation and Fill process. Consequently, Ford Motor Company Advanced Manufacturing Technology Development, Sandalwood Enterprises, Kettering University, and Dominion Tool & Die conducted a detailed project on this subject.
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