Banca de QUALIFICAÇÃO: RICARDO ALEX DANTAS DA CUNHA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : RICARDO ALEX DANTAS DA CUNHA
DATE: 20/11/2019
TIME: 09:00
LOCAL: Sala 414 do CTEC - UFRN
TITLE:

MECHANICAL BEHAVIOR OF AN INTRAPLY/WICK COMPOSITE SUBJECTED TO LOW VELOCITY IMPACT IN STRESS CONCENTRATION PRESELECTION: AN EXPERIMENTAL AND ANALYTICAL ANALYSIS

KEY WORDS:

Impact Drop Test; Post-Impact Bending; Intraply/wick Composite; Stress Concentration; Damage.

PAGES: 145
BIG AREA: Engenharias
AREA: Engenharia Mecânica
SUMMARY:

Combining the mechanical properties and the different structural applications of hybrid composite materials, I became interested in seeking results that evaluate such properties. Therefore, this thesis aims to perform an experimental analysis to determine the residual flexural strength after impact with and without stress concentration and to model this behavior analytically by means of finite elements. Two types of polymeric matrix composite laminates were developed, both with 11 layers, being a hybrid intraply/wick composite composed of 8 layers of bidirectional fabric with E-glass fiber and 3 layers of hybrid kevlar/glass (LHKV) woven bidirectional fabric located at the ends and in the center of the laminate, submitted to impact energies of 76 and 100 J, and a second laminate reinforced only by bidirectional E-glass fabric (LFV) subjected to impact energies of 46 and 61 J. A comparison was made of the presence of geometric discontinuity (16 mm hole) in the center of the test specimens for bending strength before and after impact, to evaluate the effect of the stress concentrator, hybridization and damage formation. The experimental results showed that the hybrid wick fabric improved the impact strength supporting a higher sequence of high-energy impacts when compared to other studies in the literature, presenting a reduction of the damage area, with low delamination as a possibility of repair, as well as the recovery of its residual properties. The analytical results were coherent and satisfactory and served to validate the experimental data.

BANKING MEMBERS:
Interno - 434906 - AVELINO MANUEL DA SILVA DIAS
Interno - 2941160 - JOSE HERIBERTO OLIVEIRA DO NASCIMENTO
Presidente - 1338331 - RAIMUNDO CARLOS SILVERIO FREIRE JUNIOR