Influence of hole quality on fatigue life of drilled CFRP with the different ply orientation angle

Author(s):  
Burak Yenigun ◽  
Erol Kilickap
Author(s):  
P. K. Karsh ◽  
Bindi Thakkar ◽  
R. R. Kumar ◽  
Abhijeet Kumar ◽  
Sudip Dey

The delamination is one of the major modes of failure occurring in the laminated composite due to insufficient bonding between the layers. In this paper, the natural frequencies of delaminated S-glass and E-glass epoxy cantilever composite plates are presented by employing the finite element method (FEM) approach. The rotary inertia and transverse shear deformation are considered in the present study. The effect of parameters such as the location of delamination along the length, across the thickness, the percentage of delamination, and ply-orientation angle on first three natural frequencies of the cantilever plates are presented for S-glass and E-glass epoxy composites. The standard eigenvalue problem is solved to obtain the natural frequencies and corresponding mode shapes. First three mode shape of S-Glass and E-Glass epoxy laminated composites are portrayed corresponding to different ply angle of lamina.


2019 ◽  
Vol 38 (10) ◽  
pp. 478-491 ◽  
Author(s):  
Ranfeng Wei ◽  
Guang Pan ◽  
Jun Jiang ◽  
Kechun Shen

This paper is devoted to the buckling problem of the composite cylindrical shell subjected to hydrostatic pressure. Both analytical and numerical methods are applied to investigate the buckling behavior. Based on the study of analytical formulas, it is found that the composite cylindrical shells with the same length-to-diameter ratio, diameter-to-thickness ratio, and type of layup have the same buckling pressure. Thus, a scale model experiment method is then proposed, which uses the scale model to replace the full-scale model in pressure test experiment to reduce the manufacturing cost of the test specimen. The feasibility of this method is verified by numerical calculation. The influences of ply orientation angle and length of shell on buckling shape and critical buckling pressure have been investigated numerically and demonstrated by several examples. Based on the study of the influence of shell length on critical buckling pressure, a modified finite element model, which can overcome the conservatism of optimization result due to the stress concentration caused by boundary conditions, is combined with the genetic algorithm to optimize the laminations for mass reduction.


Author(s):  
Nitish Bajaj ◽  
Rachit Chhabra ◽  
Rajat Sharma ◽  
Neerav Gupta ◽  
Dr Vipin

2019 ◽  
Vol 300 ◽  
pp. 15005
Author(s):  
Marta Kurek

The paper presents the estimation of the fatigue life under multiaxial cyclic loading of two construction materials. The main aim of this paper is to present a new method which allows evaluation of fatigue life during the design and construction phase of machine elements. In paper three well known multiaxial fatigue criteria based on the critical plane approach verified. This paper contains a proposition to define a new way of determining an orientation angle of the critical plane. The comparison between experimental and theoretical results varying the critical plane orientation appears to be satisfactory.


2020 ◽  
Vol 34 (07n09) ◽  
pp. 2040013
Author(s):  
R. Murakami ◽  
A. Fajri ◽  
W. Solafide

In this study, two kinds of bioplastic materials, where the first consists of 10% PLA, corn starch of 80% and CaCO3 10%, and the second consists of 45% PLA content, corn starch of 45% and CaCO3 10%, were used. The composites were also reinforced by the carbon fibers, which were prepared with one and two layers of carbon fiber and then ply orientations of [0[Formula: see text]] and [45[Formula: see text]]. The maximum tensile strength was observed for PLA 45% with a [0[Formula: see text]] ply orientation of two layers of carbon fiber. For composite with two layers of carbon fiber, the tensile strength showed higher for the [0[Formula: see text]] ply orientation than for the [45[Formula: see text]] ply orientation. The fatigue strength strongly depends on the orientation of carbon fiber, but in the long fatigue life range, the difference of fatigue strength between the fiber ply orientations reduces.


1995 ◽  
Vol 05 (C8) ◽  
pp. C8-1223-C8-1228
Author(s):  
N. Hagemeister ◽  
L'H. Yahia ◽  
E. Weynant ◽  
T. Lours

2020 ◽  
Vol 117 (6) ◽  
pp. 615
Author(s):  
Ping Shen ◽  
Lei Zhou ◽  
Qiankun Yang ◽  
Zhiqi Zeng ◽  
Kenan Ai ◽  
...  

In 38MnVS6 steel, the morphology of sulfide inclusion has a strong influence on the fatigue life and machinability of the steel. In most cases, the MnS inclusions show strip morphology after rolling, which significantly affects the steel quality. Usually, the MnS inclusion with a spherical morphology is the best morphology for the steel quality. In the present work, tellurium was applied to 38MnVS6 micro-alloyed steel to control the MnS inclusion. Trace tellurium was added into 38MnVS6 steel and the effect of Te on the morphology, composition, size and distribution of MnS inclusions were investigated. Experimental results show that with the increase of Te content, the equivalent diameter and the aspect ratio of inclusion decrease strikingly, and the number of inclusions with small aspect ratio increases. The inclusions are dissociated and spherized. The SEM-EDS analysis indicates that the trace Te mainly dissolves in MnS inclusion. Once the MnS is saturated with Te, MnTe starts to generate and wraps MnS. The critical Te/S value for the formation of MnTe in the 38MnV6 steel is determined to be approximately 0.075. With the increase of Te/S ratio, the aspect ratio of MnS inclusion decreases and gradually reaches a constant level. The Te/S value in the 38MnVS6 steel corresponding to the change of aspect ratio from decreasing to constant ranges from 0.096 to 0.255. This is most likely to be caused by the saturation of Te in the MnS inclusion. After adding Te in the steel, rod-like MnS inclusion is modified to small inclusion and the smaller the MnS inclusion, the lower the aspect ratio.


2020 ◽  
Vol 41 (4) ◽  
pp. 491-497
Author(s):  
V. B. Balyakin ◽  
◽  
E.P Zhilnikov ◽  
K. K Pilla ◽  
◽  
...  

Sign in / Sign up

Export Citation Format

Share Document