scholarly journals Closure to “Discussions of ‘Influence Coefficients of Tapered Cantilever Beams Computed on SEAC’” (1953, ASME J. Appl. Mech., 20, pp. 443–444)

1953 ◽  
Vol 20 (3) ◽  
pp. 444
Author(s):  
Samuel Levy
Keyword(s):  
Cantilever Beams ◽  
Influence Coefficients

Influence Coefficients of Tapered Cantilever Beams Computed on SEAC

1953 ◽  
Vol 20 (1) ◽  
pp. 131-133
Author(s):  
Samuel Levy
Keyword(s):  
Cantilever Beam ◽  
Computing Time ◽  
National Bureau ◽  
Cantilever Beams ◽  
Automatic Computer ◽  
Influence Coefficients ◽  
Basic Code ◽  
The Given

Abstract A description is given of a method for computing the influence coefficients in bending of a nonuniform cantilever beam using a basic code devised for the National Bureau of Standards electronic automatic computer SEAC. The given data for a particular problem are n, the number of stations at which influence coefficients are desired; EI0, EI1, … EIn, the bending stiffnesses at the root and at successive stations; and l1, l2, … ln, the distances between these stations. The basic code can be used in any case where the number of stations n is fewer than 23. In an example for a beam having 9 stations, the computing time was 3 min.

Improved Autoadhesion Measurement Method for Micromachined Polysilicon Beams

1996 ◽  
Vol 444 ◽  
Author(s):  
Maarten P. de Boer ◽  
Terry A. Michalske
Keyword(s):  
Surface Chemistry ◽  
Optical Microscopy ◽  
Measurement Method ◽  
Current Practice ◽  
Cantilever Beams ◽  
Beam Length ◽  
Substrate Adhesion

AbstractWe have measured autoadhesion (e.g. stiction) of individual polysilicon beams by interferometric optical microscopy. Untreated cantilever beams were dried from water in air, while treated beams were coated with a hydrophobic molecular coating of octadecyltrichlorosilane (ODTS). Adhesion values obtained for beams adhered to the substrate over a long length (large d) are independent of beam length with values of 16.7 and 4.4 mJ/m2 for untreated and treated samples respectively. These values can be understood in terms of differences in surface chemistry and polysilicon roughness. Using the shortest length beam which remains attached to the substrate, adhesion values were 280 and 16 mJ/m2 respectively. These higher values may be a result of capillarity effects. We recommend that measurements be made on beams in which d is large, in contrast to the current practice of noting the shortest beam adhered.

Estimation of the severity of damage produced by a transverse crack

2020 ◽  
Vol 65 (1) ◽  
pp. 137-144
Author(s):  
Marius-Vasile Pop
Keyword(s):  
Transverse Crack ◽  
Bending Moment ◽  
Cantilever Beams ◽  
Trend Line ◽  
The Real ◽  
Symmetrical Deformation ◽  
Frequency Drop ◽  
Equidistant Points ◽  
Fixed End ◽  
Crack Position

This paper presents a method to find the severity of a crack for cantilever beams that can be used to estimate the frequency drop due to the crack. The severity is found for the crack located at the location where the biggest curvature (or bending moment) is achieved. Because the fixing condition does not permit a symmetrical deformation around the crack, the apparent severity is smaller as the real one. The latter is found by the estimated value of the trend-line at the fixed end, it being constructed on points that consider the crack position (equidistant points in the proximity of the fixed end) and the resulted deflections.

Split beam method for determining mode shapes of cantilever beams under multiple loading conditions

2021 ◽  
pp. 107754632110276
Author(s):  
Jun-Jie Li ◽  
Shuo-Feng Chiu ◽  
Sheng D Chao
Keyword(s):  
Operation Mode ◽  
Point Contact ◽  
Mode Shapes ◽  
Cantilever Beams ◽  
Loading Conditions ◽  
Mechanical Responses ◽  
Relative Contribution ◽  
Resonance Frequencies ◽  
Beam Method ◽  
Multiple Loading

We have developed a general method, dubbed the split beam method, to solve Euler–Bernoulli equations for cantilever beams under multiple loading conditions. This kind of problem is, in general, a difficult inhomogeneous eigenvalue problem. The new idea is to split the original beam into two (or more) effective beams, each of which corresponds to one specific load and bears its own Young’s modulus. The mode shape of the original beam can be obtained by linearly superposing those of the effective beams. We apply the split beam method to simulating mechanical responses of an atomic force microscope probe in the “dynamical” operation mode, under which there are a stabilizing force at the positioner and a point-contact force at the tip. Compared with traditional analytical or numerical methods, the split beam method uses only a few number of basis functions from each effective beam, so a very fast convergence rate is observed in solving both the resonance frequencies and the mode shapes at the same time. Moreover, by examining the superposition coefficients, the split beam method provides a physical insight into the relative contribution of an individual load on the beam.

scholarly journals A Multi-Mode Broadband Vibration Energy Harvester Composed of Symmetrically Distributed U-Shaped Cantilever Beams

Micromachines ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 203
Author(s):  
Xiaohua Huang ◽  
Cheng Zhang ◽  
Keren Dai
Keyword(s):  
Energy Harvester ◽  
Low Frequency ◽  
Experimental Results ◽  
Vibration Energy ◽  
Cantilever Beams ◽  
Resonant Frequencies ◽  
Promising Alternative ◽  
Piezoelectric Energy ◽  
Straight Beam ◽  
Resonance Frequencies

Using the piezoelectric effect to harvest energy from surrounding vibrations is a promising alternative solution for powering small electronic devices such as wireless sensors and portable devices. A conventional piezoelectric energy harvester (PEH) can only efficiently collect energy within a small range around the resonance frequency. To realize broadband vibration energy harvesting, the idea of multiple-degrees-of-freedom (DOF) PEH to realize multiple resonant frequencies within a certain range has been recently proposed and some preliminary research has validated its feasibility. Therefore, this paper proposed a multi-DOF wideband PEH based on the frequency interval shortening mechanism to realize five resonance frequencies close enough to each other. The PEH consists of five tip masses, two U-shaped cantilever beams and a straight beam, and tuning of the resonance frequencies is realized by specific parameter design. The electrical characteristics of the PEH are analyzed by simulation and experiment, validating that the PEH can effectively expand the operating bandwidth and collect vibration energy in the low frequency. Experimental results show that the PEH has five low-frequency resonant frequencies, which are 13, 15, 18, 21 and 24 Hz; under the action of 0.5 g acceleration, the maximum output power is 52.2, 49.4, 61.3, 39.2 and 32.1 μW, respectively. In view of the difference between the simulation and the experimental results, this paper conducted an error analysis and revealed that the material parameters and parasitic capacitance are important factors that affect the simulation results. Based on the analysis, the simulation is improved for better agreement with experiments.

scholarly journals Environmental Behavior Spillover or Public Information Induction: Consumers’ Intention to Pay a Premium for Rice Grown with Green Manure as Crop Fertilizer

Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1285
Author(s):  
Fuduo Li ◽  
Kangjie Zhang ◽  
Aibo Hao ◽  
Changbin Yin ◽  
Guosheng Wu
Keyword(s):  
Green Manure ◽  
Environmental Governance ◽  
Agricultural Sector ◽  
Environmental Behavior ◽  
Public Information ◽  
Chinese Consumers ◽  
Environmental Behaviors ◽  
Policy Makers ◽  
Influence Coefficients ◽  
Structural Research

Nowadays, there is a growing interest in pro-environmental foods produced by pro-environmental practices. However, consumers’ payment motivations towards such foods are currently poorly understood. This manuscript provided a critical investigation of Chinese consumers’ intention to pay a premium (ITPP) for rice grown with green manure as crop fertilizer (GMR). One focus was the establishment of an explanatory structural research framework that includes effects of environmental behavior spillover (EBS) and public information induction (PII); another focus was to analyze the impacts of the selected structural elements on ITPP by introducing education as a moderator. Results suggest that consumers’ ITPP can be largely influenced by PII, therefore, for GMR marketers and policy makers, measures should be developed to widen consumers’ access to public information related to GMR and to improve their capacity of screening effective information. EBS, when ITPP remains low, emerged as a pivotal predictor of consumers’ ITPP. This observation provides us with the enlightenment that breeding consumers’ daily environmental behaviors is highly valued to inspire their payment intention in the early stages of GMR market development. Another finding is that, with the introduction of the educational variable, the influence coefficients of EBS and PII on ITPP increased from 0.42 and 0.53 to 0.61 and 0.66, respectively, which means that it is possible to boost consumers’ payment intention by improving their educational attainment. This study contributes to the existing literature by providing empirical evidence for the GMR industrial upgrading strategy and have significant implications for the environmental governance of the agricultural sector.

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