A rigorous first order shear deformation theory (FSDT) is employed along with modified ABD parameters to analyze static and free vibration behavior of generally laminated beams and shafts. Different approaches for calculating composite beam stiffness parameters have been considered and the most accurate one that accounts for material couplings have been used to analyze static and free vibration behaviors of straight beams with different laminates and boundary conditions. In order to analyze curved beams, the term (1+z/R) is exactly integrated into ABD parameters formulation and an equivalent modulus of elasticity is used instead of traditional stiffness terms to account for both the deepness and material coupling of the beam structures. The model has been solved analytically for simply supported boundary conditions and the general differential quadrature (GDQ) technique has been used for other boundary conditions. The results for deflection, moment resultants, and natural frequencies of straight and curved beams with different deepness ratio (often called depth ratio), slenderness ratio, lamination, and boundary conditions are compared with those obtained from accurate three dimensional finite element simulations using ANSYS. The results were in close proximity to three dimensional finite element results. The model is then applied to transverse vibration analysis of multi-span generally laminated composite shafts with a lumped mass using GDQ. The results for natural frequencies are compared to experimental and other analytical models as well as finite element simulation. The results in the present analyses were found accurate. Conclusively, it has been shown that when considering more accurate stiffness parameters, a First Order Shear Deformation Theory can accurately predict static and free vibration behaviors of composite beams and multispan shafts of any deepness, lamination and boundary conditions.

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本論文は，従来よりも信頼性や効率が良く実用的に構造物の振動・騒音を低減することを目指して，実験および解析技術に対する新たなアプローチを確立することを目的としている．そのために，統計的エネルギー解析法と伝達経路解析法を統合することで，両者の入力を相互利用可能な手法を提案し，構造物の振動・騒音の低減を支援するための，実験および解析手法を構築した． / In this thesis, we have established new theoretical approaches as well as some basic practical applications in the development of noise and vibration analysis for structures involving transfer path and sound source from airborne noise and structure-borne noise. These new approaches were extracted from the existing experimental and analysis technique of noise and vibration for structures, which will improve their efficiency and reliability for noise and vibration reduction on industrial machineries as well as other machines. / 博士(工学) / Doctor of Philosophy in Engineering / 同志社大学 / Doshisha University

FläktGroup is one of the world’s largest supplier of products and solutions related to indoor climate control. The Jönköping location is the largest production facility for FläktGroup. Air handling equipment for commercial buildings are the company's major products, while ventilation and air treatment are its primary business. An air handling unit is used to continually exchange indoor air for outdoor air in order to accomplish the desired air exchange in a structure. The air handling unit is used to heat, chill, and filter incoming air in addition to using fans to move air into and out of the building and exchange heat between incoming and exiting air. To further increase the lifecycle of the current fan-walls. FläktGroup had a study done by a student to see if it was possible to decrease the vibrations on the fan-wall. Since a decrease in vibrations will results less stress on the bearings and increase the lifecycle. Which in turn means that the product needs to be replaced less often and have less maintenance done. The study will be following FläktGroups steps for a product development. The overall project can be divided in the following steps: 1. Project definition – 2. Concept generation – 3. First selection of candidate concepts – 4. CAD design of candidate concept(s) – 5. Prototype build –6. Verification in lab – 7. Conclusion. The study will mainly focus on step 2-7. Due to the complexity of the study, it will have a experimental approach, which means that no calculations will be done and everything will be done by experimenting and verifications through data collection software. The main focus to reduce vibration on the air handling unit was to modify and improve upon existing fan-walls, either to stiffen it or cushion it. The theory used for this was a simple vibration formula that contained the correlation of stiffness, mass, and damping. Through the process given by FläktGroup three main concepts were chosen as candidates to further test on and finally one concept was picked to pursue. A horizontal beam that reduced vibrations considerably. A concept that showed extra potential was also found, however not enough testing was done and is encouraged to be tested more upon in the future.

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This study was a randomized control trial. The purpose of this study was threefold: 1) to determine if intramuscular temperature (IMt) increases in the semitendinosus (ST) are similar to the vastus lateralis (VL) during standard WBV static squatting; 2) to determine if changes in intramuscular temperature of the hamstrings is different from a standard static semi-squat when undergoing WBV in a static stretching position; and 3) to determine if shorter overall durations as is typically used for stretching protocols (i.e. 5 repetitions of 30s each), will result in IMt increases. Twelve subjects (all males), with tight hamstrings completed this study (age 23.5 ± 1.5 years; body mass 76.3 ± 17.7 kg; height 177.8 ± 15.2 cm). Subjects were randomly assigned to treatment order of three groups: semi squat vibration (SQ), vibration with static stretch (VS), and static stretch only (SS). Subjects reported to the lab 3x, each visit separated by one week to receive all treatments. Each treatment day consisted of baseline temperature measurements in the VL and ST and following each of 2 sets (5x60-second for SQ, 5x30-second for VS and SS, with 30 seconds rest in between reps). Post-hoc comparisons revealed that VL temperature increases were significantly greater from baseline than the hamstrings at all three time periods (p<.0001). There were no significant differences found in ST IMt when comparing 5-minutes of total WBV in the VS condition (both sets of 2.5 minute bouts) to 5-minutes of vibration in the SQ condition (p=1.000), or between VS and SS after 5 minutes (p=.9827). Post-hoc comparisons between SS and VS conditions revealed no significant differences after 2.5 minutes (p=1.000), 5 minutes (p=.8812), and 10-minutes post vibration (p=.9844) in ST or VL (p=1.000, p=.0540, and p=.1815 respectively) temperature. The results of our study show that the ST does not exhibit similar increases in IMt as the VL when performing standard semi-squat WBV training. The IMts seen in the static stretch both with and without vibration seem to suggest that factors other than IMt most likely contribute to flexibility changes seen in prior WBV flexibility studies.

Some have suggested acute increases in musculotendinous stiffness (k) following whole body vibration (WBV). Others propose that chronic ankle instability (CAI) may alter k of the lower extremity. Changes in proprioceptive activity and/or gamma motoneuron activation post-WBV and/or due to CAI could lead to alterations in k. However, little is known about acute effects of WBV on k and less is known about changes in k with CAI. PURPOSE: Assess differences in vertical and joint k between healthy and CAI subjects during single-limb landings and detect alterations in k measures post-vibration. METHODS: Subjects were identified as CAI via the FAAM, MAII and special testing. Thirty-five CAI subjects (17 males, 18 females; age = 22 ± 7 yr; height = 1.73 ± 0.23 m; mass = 70 ± 30 kg) and 35 matched healthy subjects (17 males, 18 females; age = 23 ± 5 yr; height = 1.73 ± 0.21 m; mass = 70 ± 35 kg) qualified for this study. Kinetic (2000 Hz) and kinematic (250 Hz) data were recorded during several jump landings pre- and post-WBV. Five repetitions of WBV, at 26 Hz and 4 mm amplitude, were introduced between pre- and post-WBV jump trials. The jump task included a double-limb jump followed by a single-limb landing and a subsequent contralateral hop. Vertical k (∆vertical GRF/center of mass vertical displacement), hip, knee and ankle joint k (∆joint moment/∆joint angle) were calculated, averaged across five successful pre-WBV and across six post-WBV trials. An ANOVA was used to detect between-group differences, while an ANCOVA was used to analyze within-group differences post-WBV using pre-measures as covariates. A pseudo-Bonferroni adjustment was performed prior to statistical analysis (p < 0.01). RESULTS: No between-group differences were observed for any of the variables (F1,68 = 0.020 to 1.400, p = 0.240 to 0.890). A significant increase in vertical k was observed post-WBV for the healthy group (t67 = 2.760, p = 0.008), but not for the CAI group (t67 = 0.370, p = 0.720). The CAI group did demonstrate a decrease in ankle (t67 = -3.130, p = 0.003) and knee (t67 = -3.490, p = 0.001) joint k post-vibration. No other within-group differences were observed post-WBV (p > 0.01). CONCLUSIONS: It appears that WBV does acutely increase vertical k in healthy subjects. However, this treatment effect was not observed in CAI. Further research is needed to assess how k is regulated in CAI subjects and why CAI subjects responded differently to WBV.

Gymnasts must attain extreme ranges of flexibility to execute performance requirements, thus effective stretching proves vital to advancement in the sport. This study examined the acute effects of whole-body vibration (WBV) on passive and dynamic flexibility in young, female gymnasts. Participants (n = 27, Junior Olympic levels 5-10) served as their own control. Measurements of passive and dynamic flexibility were obtained using the TOPS forward split testing method to examine passive flexibility and dynamic flexibility was measured via split jumps that were analyzed with video and Dartfish software. According to randomized order, all participants completed a stretching protocol either with the WBV platform turned on (VIB) or off (C) separated by 48 h. Participants performed 4 sets of three stretches on the WBV platform. An ANCOVA was performed (using height, weight, age, years of experience, and gymnastics level as covariates). Significant improvements were found in passive flexibility for both VIB and C conditions, but there was no significant difference between the two stretching conditions (p = 0.17). The maximum split jump decreased significantly from pre to post measurement in both the VIB (p < 0.0001) and C (p = 0.04) conditions. VIB decreased the split jump significantly more than C. Based on the results of our study, an acute session of static stretching or stretching with WBV immediately before performance decreases split jump performance. Therefore, this WBV protocol is not recommended immediately prior to gymnastics competition.

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