http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Chenhui Ren (검색결과 2 건)
- 무료
- 기관 내 무료
- 유료
-
Impact resistance performance and optimal design of a sandwich beam with a negative stiffness core
Chenhui Ren,Deqing Yang,Qing Li 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.7
Numerical analyses were carried out to investigate the response of a sandwich beam with a negative stiffness (NS) core under quasistatic compression and low-velocity impact at the center. By varying the thicknesses of face sheets and interlayers and the lengths of segments, a parametric study on the impact resistance of the sandwich beam is conducted. The maximal deflection of the top face sheet and the strain energy stored in the NS beam were recorded at the moment when the impactor’s velocity decreased to zero. Based on the impact simulation, a multi-objective optimization problem on the beam configuration was set up to find out the most efficient antideformation design at the impact velocity of 2500 mm/s. To solve the problem with the surrogate model method, an optimal Latin hypercube sampling (OLHS) technique and a two-phase differential evolution (ToPDE) algorithm were utilized to generate calculation points in the design space, respectively. Then different surrogate models including the RSM model, the Kriging model and the RBF model, were compared to give the best approximation of the original problem. In the end, the genetic algorithm (GA) dealing with discrete optimization problems was employed to obtain the optimum solutions. Results indicate that different parts of the NS beam dominate the resistance to deformation under different levels of impact intensity. The largest portion of the strain energy is stored in the four curved plates. In the obtained optimization solution, the longest segment is near the two ends and the flat plates near the top are thicker, which is instructive to the beam design on improving impact resistance.
-
Yanyan Ren,Hongfeng Li,Guanglei Wu,Le Yang,Chenhui Zheng,LIUDING WANG,Fang Ren,Hui Xing,HONGJING WU 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2016 NANO Vol.11 No.2
Al/Fe/Co doped ordered mesoporous carbon (OMC) composites have been synthesized by a facile method, and the influence of dopant on the electromagnetic (EM) and microwave absorption properties was investigated in the frequency range of 2–18 GHz. Compared with Fe/Co– OMC composites, the Al–OMC nanocomposite played a great role in adjusting values and frequency dependence of complex permittivity, which gives rise to significant improved microwave absorption and reduced thickness of the corresponding paraffin wax composites. Reflection loss (RL) values less than -5 dB and -10 dB were obtained in the frequency range of 9.2–18 GHz and 10.7–14.7 GHz with a single thickness of 2.00 mm, respectively. Such enhanced EM wave absorption property of the Al–OMC/paraffin wax composite was ascribed to its superior impedance matching characteristic. Thin thickness, broadband absorption microwave absorbers with Al doped OMC nanocomposites were obtained.
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
