This paper presents an experimental study of the broadband energy harvesting and dynamic responses of an L-shaped piezoelectric cantilever beam.Experimental results show that the L-shaped piezoelectric beam generates ...This paper presents an experimental study of the broadband energy harvesting and dynamic responses of an L-shaped piezoelectric cantilever beam.Experimental results show that the L-shaped piezoelectric beam generates two optimal voltage peaks when the horizontal beam size is similar to the vertical beam size.Several optimized L-shaped piezoelectric cantilever beam structures are proposed.Power generation using the inverted bistable L-shaped beam is better.It is observed experimentally that the inverted bistable L-shaped beam structure shows obvious bistable characteristics and hard spring characteristics.Furthermore,the corresponding relationship between the bistable phase portrait and the potential energy curve is found in the experiment.This is the first time that a phase portrait for stiffness hardening of an L-shaped beam has been found experimentally.These results can be applied to analysis of new piezoelectric power generation structures.展开更多
This paper presents the results of a research project aimed at providing standard circular web openings to the popular precast pretensioned inverted T-beam.Opening size and placement and required materials strengths w...This paper presents the results of a research project aimed at providing standard circular web openings to the popular precast pretensioned inverted T-beam.Opening size and placement and required materials strengths were investigated.In this paper the nonlinear analysis and design of simply supported pretensioned inverted T-beam with circular web openings are presented.Two design parameters are varied:opening location and number of openings.The results from nonlinear finite element analysis were substantiated by test results from five pretensioned inverted T-beams with web opening and one solid beam.Good agreement is shown between the theoretical and the experimental results.The test results obtained from this investigation show that the performance of the specimens with web openings is almost identical to that of the specimen without web openings.A simple design method for pretensioned inverted T-beam with circular web openings is proposed.展开更多
The provision of transverse openings in floor beams to facilitate the passage of utility pipes and service ducts not only results in a more systematic layout of pipes and ducts,it also translates into substantial econ...The provision of transverse openings in floor beams to facilitate the passage of utility pipes and service ducts not only results in a more systematic layout of pipes and ducts,it also translates into substantial economic savings in the construction of a multi-storey building.In this paper,ultimate load analysis of statically loaded simply supported pretensioned inverted T-beams with circular web openings is presented.Major findings relevant to ultimate load analysis of pretensioned beams with circular web openings are summarized.An attempt has been made to answer the frequently asked questions related to ultimate load analysis on multiple circular web open-ings.It has been shown that the analysis method for pretensioned beams with multiple large circular web openings can be further simplified without sacrificing rationality.展开更多
基金supported by the National Natural Science Foundation of China(Grants 11772008,11172009,11372015,11232009,10872010,11290152,10732020)the Tianjin Natural Science Foundation(Grant 19JCZDJC32300).
文摘This paper presents an experimental study of the broadband energy harvesting and dynamic responses of an L-shaped piezoelectric cantilever beam.Experimental results show that the L-shaped piezoelectric beam generates two optimal voltage peaks when the horizontal beam size is similar to the vertical beam size.Several optimized L-shaped piezoelectric cantilever beam structures are proposed.Power generation using the inverted bistable L-shaped beam is better.It is observed experimentally that the inverted bistable L-shaped beam structure shows obvious bistable characteristics and hard spring characteristics.Furthermore,the corresponding relationship between the bistable phase portrait and the potential energy curve is found in the experiment.This is the first time that a phase portrait for stiffness hardening of an L-shaped beam has been found experimentally.These results can be applied to analysis of new piezoelectric power generation structures.
基金The authors gratefully acknowledge financial supports from Universiti Malaysia Pahang(UMP)through Short-Term Grant(Grant No.FR56398)Ministry of Science,Technology and Innovation(MOSTI)through e-science fund(Grant No.03-02-03 SF0115).
文摘This paper presents the results of a research project aimed at providing standard circular web openings to the popular precast pretensioned inverted T-beam.Opening size and placement and required materials strengths were investigated.In this paper the nonlinear analysis and design of simply supported pretensioned inverted T-beam with circular web openings are presented.Two design parameters are varied:opening location and number of openings.The results from nonlinear finite element analysis were substantiated by test results from five pretensioned inverted T-beams with web opening and one solid beam.Good agreement is shown between the theoretical and the experimental results.The test results obtained from this investigation show that the performance of the specimens with web openings is almost identical to that of the specimen without web openings.A simple design method for pretensioned inverted T-beam with circular web openings is proposed.
基金The authors gratefully acknowledge the financial support from the Universiti Malaysia Pahang(UMP)through a short-term grant(Grant No.FR56398)from the Ministry of Science,Technology and Innovation(MOSTI)through an e-science fund(Grant No.03-02-03 SF0115).
文摘The provision of transverse openings in floor beams to facilitate the passage of utility pipes and service ducts not only results in a more systematic layout of pipes and ducts,it also translates into substantial economic savings in the construction of a multi-storey building.In this paper,ultimate load analysis of statically loaded simply supported pretensioned inverted T-beams with circular web openings is presented.Major findings relevant to ultimate load analysis of pretensioned beams with circular web openings are summarized.An attempt has been made to answer the frequently asked questions related to ultimate load analysis on multiple circular web open-ings.It has been shown that the analysis method for pretensioned beams with multiple large circular web openings can be further simplified without sacrificing rationality.
