scholarly journals Assessment on the Designed Structural Frame of the Automatic Thickness Checking Machine – Numerical Validation in FE method

2021 ◽  
Vol 33 ◽  
pp. 59-66
Author(s):  
Muhammad Faiz Dzulfiqar ◽  
Aditya Rio Prabowo ◽  
Ridwan Ridwan ◽  
Haris Nubli
Author(s):  
Guobiao Ji ◽  
Liang Cheng ◽  
Shaohua Fei ◽  
Jiangxiong Li ◽  
Yinglin Ke

Through-thickness reinforcement is a promising solution to the problem of delamination susceptibility in laminated composites. Modeling Z-pin–prepreg interaction is essential for accurate robotics-assisted Z-pin insertion. In this paper, a novel Z-pin insertion force model combining the classical cohesive finite element (FE) method with a dynamic analytical fracture mechanics model is proposed. The velocity-dependent cohesive elements, in which the fracture toughness is provided by the analytical model, are implemented in Z-pin insertion FE model to predict the crack initiation and propagation. Then Z-pin insertion experiments are performed on prepreg sample with metallic Z-pins at different velocities to identify the analytical model parameters and validate the simulation predictions offered by the model. Dynamics of Z-pin interaction with inhomogeneous prepreg is described and the effects of insertion velocity on prepreg contact force are studied. Results show that the force model agrees well with experiments and the fracture toughness rises with the increasing Z-pin insertion velocity.


2021 ◽  
pp. 002199832110335
Author(s):  
Osman Kartav ◽  
Serkan Kangal ◽  
Kutay Yücetürk ◽  
Metin Tanoğlu ◽  
Engin Aktaş ◽  
...  

In this study, composite overwrapped pressure vessels (COPVs) for high-pressure hydrogen storage were designed, modeled by finite element (FE) method, manufactured by filament winding technique and tested for burst pressure. Aluminum 6061-T6 was selected as a metallic liner material. Epoxy impregnated carbon filaments were overwrapped over the liner with a winding angle of ±14° to obtain fully overwrapped composite reinforced vessels with non-identical front and back dome layers. The COPVs were loaded with increasing internal pressure up to the burst pressure level. During loading, deformation of the vessels was measured locally with strain gauges. The mechanical performances of COPVs designed with various number of helical, hoop and doily layers were investigated by both experimental and numerical methods. In numerical method, FE analysis containing a simple progressive damage model available in ANSYS software package for the composite section was performed. The results revealed that the FE model provides a good correlation as compared to experimental strain results for the developed COPVs. The burst pressure test results showed that integration of doily layers to the filament winding process resulted with an improvement of the COPVs performance.


2020 ◽  
Vol 55 (1) ◽  
pp. 83-99
Author(s):  
Lukas Hermann

AbstractIn its peritext, Thomas Mann’s Entstehung des Doktor Faustus is described as a “Roman eines Romans”. The essay reasons that this description of its genre as well as structural aspects of its composition mark it as an autobiographical text. Instead of following most studies on the Doktor Faustus, which regard the Entstehung simply as a documentary source for exposing autobiographical intricacies of Mann’s novel, textual evidence for the Entstehung’s autonomy is given. The analysis focuses first on the structural frame of the Entstehung in order to show Mann’s central techniques of autobiographical self-stylization. In this context auto-fictional elements can also be identified. Exemplary passages from two longer sections are taken into account based on these findings. While the Doktor Faustus is a recurrent topic in these passages, it is not, by any means, the only one. Combined with varying autobiographical writing techniques, the Entstehung is thus displaying continuous independence from the Faustus. Based on these insights, future Mann studies on both works may reevaluate the role of the Entstehung for the reception of the Faustus and the status of autobiographical literature in the works of Thomas Mann.


Author(s):  
Wenping Xue ◽  
Pan Jin ◽  
Kangji Li

The actuator fault estimation (FE) problem is addressed in this study for the quarter-car active suspension system (ASS) with consideration of the sprung mass variation. Firstly, the ASS is modeled as a parameter-dependent system with actuator fault and external disturbance input. Then, a parameter-dependent FE observer is designed by using the radial basis function neural network (RBFNN) to approximate the actuator fault. In addition, the design conditions are turned into a linear matrix inequality (LMI) problem which can be easily solved with the aid of LMI toolbox. Finally, simulation and comparison results are given to show the accuracy and rapidity of the proposed FE method, as well as good adaptability against the sprung mass variation. Moreover, a simple FE-based active fault-tolerant control (AFTC) strategy is provided to further demonstrate the effectiveness and applicability of the proposed FE method.


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