Abstract
The very first opportunity to showcase a vehicle’s superior built quality to the customer is through its doors. Things like touch and feel of the handle, efforts and door closing/opening sounds plays a vital role in creating a good impression. Right from the first interaction with the car in a showroom to everyday usage, door closing/opening sounds are the ones that customer will hear often. Hence, it is important to utilize this factor to display the brand image of the vehicle by tuning for a signature closure sound. But the present trend of light weighting makes it more challenging to produce a sound as good as that of the heavier doors. The prerequisite for achieving this goal is to identify the individual noise contributors during the complex door and body interaction event while opening/closing. Door closing is a transient event and the transfer function involved is not a time constant. This makes it complicated to do a contribution analysis using regular NVH methods or a traditional transfer Path Analysis (TPA). This paper deals with the application of time domain TPA technique for the door slam noise to identify the contributions from the major systems like latch, striker, seals & body. The major advantages of this methodology is that it is quicker, repeatable and executed with limited number of sensors. This study also quantifies the structure borne and airborne contributions from major systems. Once all the contributions are identified and separated, each of these individual transfer functions were modified to synthesize an artificial door sound. These synthesized sounds will be helpful in understanding which component needs to be modified and also showcase the predicted end result due to that modification. Another advantage of this technique is that it works in the time domain and thus we can play back and listen to the sound at each stage of the synthesis in order to achieve target acoustic door signature.