# Improvement of Boeing Bump Method Considering Aircraft Vibration Superposition Effect
## 6 Conclusions  
By adopting a single bump as the standard, the Boeing Bump ignores multiple bump superpositions. In this study, we carried out aircraft dynamic simulations by first establishing five typical virtual prototype models and then quantifying the superposition effect of the aircraft vibration responses under multiple bumps. Based on this work, we then back-calculated the modified Boeing Bump at different wavelengths according to the dynamic response thresholds. The main points of this study are as follows.  
1. We developed and verified the reliability of the B737-800, B757-200, B777-300 ER, B787-800, and B747-400 virtual prototype models in this study.
2. The most unfavorable speed (in terms of vibration response) of the different aircraft models differs greatly. Basically, the larger the aircraft, the higher the most unfavorable speed.
3. The aircraft's dynamic response might increase by 50% for two bumps on a rough runway compared to a single bump. Therefore, the original Boeing Bumpmethod should be improved in terms of dealing with multiple bumps.
4. Different wavelengths are associated with different aircraft types. Furthermore, the modification evaluation criteria are stricter than the criteria for the original Boeing Bump, especially for middle and long waves on the runway.  
Conceptualization, S.L. and Y.T.; methodology, S.L. and Y.T.; validation, S.L. and Y.T.; investigation, S.L. and Y.T.; resources, S.L. and Y.T.; data curation, S.L. and Y.T.; writing--original draft preparation, S.L. and Y.T.; writing--review and editing, S.L., Y.T., Z.Z., L.L. and P.X.; visualization, S.L. and Y.T.; supervision, S.L. and Y.T.; project administration, S.L. and Y.T.; funding acquisition, S.L. and Y.T. All authors have read and agreed to the published version of the manuscript.  
This study was supported by China Postdoctoral Science Foundation funded project (No.2020M681392), and the National Natural ScienceFoundation of China (Grant No. U1833123 and No.U1933113). The authors appreciate the help of [PERSON], [PERSON], et.  
**Infrared Consent Statement**: not applicable.  
**Data Availability Statement**: [1]. The [Airframe aerodynamics, Landing gear buffer system, wheels] data presented in this study are available on request from the corresponding author. The data are not publicly available due to [institution policy] [2]. The [runway profile data for Shanghai Pudong Airport Runway No. 4, Hangzhou Xiaoshan Airport Runway No. 1, Dongying Shengli Airport Runway, Ningbo Lishe Airport Runway, and Nanjing Lukou Airport Runway No. 1. ] data presented in this study are available on request from the corresponding author. The data are not publicly available due  
Figure 12: Comparison of modified and original Boeing Bump thresholds.  
to [airports internal policy]. [3]. Publicly available datasets were analyzed in this study. [B737-800 simulator] data can be found here: [[[https://www.airporttech.tc.faa.gov/Products/Airport-Pavement-Papers-Publications/Airport-Pavement-Detail/ArtMID/3684/ArticleID/159/Boeing-737-800-Final-Surface-Roughness-Study-Data-Collection](https://www.airporttech.tc.faa.gov/Products/Airport-Pavement-Papers-Publications/Airport-Pavement-Detail/ArtMID/3684/ArticleID/159/Boeing-737-800-Final-Surface-Roughness-Study-Data-Collection)]([https://www.airporttech.tc.faa.gov/Products/Airport-Pavement-Papers-Publications/Airport-Pavement-Detail/ArtMID/3684/ArticleID/159/Boeing-737-800-Final-Surface-Roughness-Study-Data-Collection](https://www.airporttech.tc.faa.gov/Products/Airport-Pavement-Papers-Publications/Airport-Pavement-Detail/ArtMID/3684/ArticleID/159/Boeing-737-800-Final-Surface-Roughness-Study-Data-Collection)) accessed on 27 February 2021] [4]. These prior studies (and datasets) are cited at relevant places within the text as references [ F. A. A., Surface Roughness Study Final Data Report Boeing 737-800. Washington, D. C: Federal Aviation Administration, 2015.].  
The authors declare no conflicts of interests.