The design method of structural design was modified from specification-based design to performance-based design by an amended Building Standards Law in 2000. Structural engineers need to elicit request information from home
owners by conversation and to determine the target performance to be attained for a performance-based design.
This study aims to improve the explanation of environmental vibration. We focus on the relationship between words that express a state of vibration and the vibration image evoked by the word. This study is based on the results of two questionnaire surveys (one with 101 respondents and the other with 32 respondents), an experiment conducted on a vibration table (with 32 respondents), and two hearing surveys (one with 7 respondents and the other with 32 respondents).
We commence the study by investigating the recognition of environmental vibration. The questionnaire results show that many respondents have felt vibration in their house, but a few respondents did not consider it an important issue. The questionnaire results regarding the types of vibration source experienced by the respondents show that vibration sources other than earthquakes (e.g., wind, railway traffic, road traffic, human footfall, etc.) have a probability lower than 0.35. Therefore, when structural engineers explain the environmental vibration expected to occur at home, the home owner has not experienced the types of vibration source in most cases. Structural engineers therefore need to provide an intelligible explanation to ensure the home owner’s understanding of the concept.
Through hearing surveys on the explanation of vibration experience by respondents, it is found that a vibration
image, which is a mental picture that the respondent recalls when she explains her own experience, consists of three elements (①the type of source the vibration originates from, ②the characteristics of the vibration, ③the magnitude of the vibration). Thus, we found that introducing the three elements into explanations of vibration is effective at making the explanation intelligible. We unveil that onomatopoeia is suitable for explaining the three elements because words can be easily connected with past experience of vibration. Furthermore, it is found that several words (“horizontal vibration” ”vertical vibration” “quick” ”long-short” ”big-small” ”like push-up” ”like swing” ) are suitable for explaining vibration too.
For explaining the three elements that constitute a vibration image, we investigate what physical properties can be expressed through the above words. With regard to ①vibration source, we show that words relating to vibration sources can express the frequency range because frequency range of vibration image from the word is similar that of actually vibration. With regard to ②vibration characteristic, we show that words that express the direction of vibration or frequency, such as “horizontal vibration” and ”vertical vibration,” are known as words expressing vibration direction. In addition, we show that onomatopoeia and terms such as “like push-up” and ”like swing” can express the direction of vibration plainly and easily. Regarding the expressions of frequency, onomatopoeia can express difference of frequency in three levels. With regard to ③magnitude of vibration, we verify that “big-small” can express the magnitude of acceleration. In addition, we show that onomatopoeia can express gradual difference of acceleration.
We show specific physical quantities such as frequency and acceleration range, which can be explained using onomatopoeic words or phrases (e.g., “gata-gata”, “yura-yura”, and “don” in Japanese), by the results of the experiment on vibration table.
Although this study presents useful results, structural engineers will need to select and match words and explanations for each individual separately.
