Correlation Between Fiber Orientation and Geometrical Shrinkage of Injected Parts Under the Influence of Flow-Fiber Coupling Effect

Chao-Tsai Huang,Jun-Zheng Wang,Cheng-Hong Lai,Sheng-Jye Hwang,Po-Wei Huang,Hsin-Shu Peng 한국정밀공학회 2023 International Journal of Precision Engineering and Vol.10 No.4

Fiber reinforced thermoplastics (FRP) have been widely used in automotive industry. However, how does the flow-fiber coupling effect influence the micro fiber orientation and further affect the geometrical shrinkage of the final part that is not fully understood yet. In this study, a complex center-gated plate has been applied to study the influence of the flow-fiber coupling effect on the fiber orientation variation and the geometrical change through numerical simulation. Then the practical verification through the micro-computed tomography (micro-CT) and image processing technology was carried out. Results show that in the presence of the flow-fiber coupling the required spruce pressure will be higher compared to no coupling case. In addition, the melt flow front pattern will be changed from “convex-flat” to “convex-concave” under the influence of this coupling. Moreover, in the presence of the flow-fiber coupling effect, the wider core width for fiber orientation tensor in the flow direction (A11) can be obtained from upstream to downstream regions for the same model. However, in the downstream region (i.e. in the FR), the flow-fiber coupling effect is more significantly due to the action of less shear rate in that region. Finally, through the measurement of the left–right asymmetrical shape of the FR for Model I (or Model II), the reason is that the flow-fiber coupling effect will switch the fiber orientation from the flow direction (A11) dominate to the cross-flow direction (A22) dominate. This asymmetrical fiber orientation distribution will further create that asymmetrical shrinkage shape of final part. The correlation between fiber orientation and geometrical shrinkage can be achieved.

Flow-induced Orientations of Fibers and Their Influences on Warpage and Mechanical Property in Injection Fiber Reinforced Plastic (FRP) Parts

Chao-Tsai Huang,Jia-Hao Chu,Wei-Wen Fu,Chia Hsu,Sheng-Jye Hwang 한국정밀공학회 2021 International Journal of Precision Engineering and Vol.8 No.3

During the past two centuries, due to too fast growth of the human population, the pollution made by human has seriously impacts on our environment, particularly, for the CO2 emission. To diminish the CO2 emission problem, one of the effective solutions is applying lightweight material, such as the fiber-reinforced plastics (FRP), to replace metal in the manufacturing of transportation vehicles. However, since the reinforced function of the fibers inside plastic matrix is very complex, it is not easy to be visualized and managed. Specifically, the connection from microstructures of the fibers to the physical properties of the final product is far from our understanding. In this study, we have proposed a benchmark with three standard specimens based on ASTM D638 with different gate designs. This system is used to study the fiber microstructures and associated mechanical properties using numerical simulation and experimental studies. Results showed that the tensile properties (including tensile modulus and tensile stress) of all three ASTM standard specimens can be improved significantly in the appearance of the fibers. Moreover, the tensile properties variation of the finished parts associated with the microstructures of the short fibers based on the gate design have been also investigated. Specifically, the tensile modulus and the strength of the Model I are greater than that of Model II, while Model III is much less than others because of its double gate effect. The reason why the tensile modulus and the strength of the Model I is greater than that of Model II is due to some entrance effect. That entrance effect will further provide flow-induced fiber orientation to melt and then enhance the tensile properties of Model I. To confirm the observation, a series simulation and experimental studies have been performed. Specifically, the fiber orientation distribution is predicted using CAE, and verified using micro-CT scan and image analysis by Avizo software. Hence, the correlation from fiber microstructure feature (particularly in fiber orientation) to tensile modulus and tensile stress for fiber reinforced thermoplastic (FRP) in injection molding process can be validated.

Experimental study and modeling of masonry-infilled concrete frames with and without CFRP jacketing

Chao-Hsun Huang,Yu-Chi Sung,Chi-Hsin Tsai 국제구조공학회 2006 Structural Engineering and Mechanics, An Int'l Jou Vol.22 No.4

Transfer matrix for rotor coupler with parallel misalignmen

Chao-Yang Tsai,Shyh-Chin Huang 대한기계학회 2009 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.23 No.5

A transfer matrix for shafts coupler with parallel misalignment (offset) was derived. The responses of a rotor system composed of flexible shafts, unbalanced disks, elastic supports and shafts coupler with misalignment were then investigated. Through the derivation, the boundary shears induced by a rotating shaft were first discovered to be coupled in two perpendicular directions. These coupling shears might reduce the first critical speed up to 50% in the free-free case. The studies showed that the shafts coupler altered the rotor’s critical speeds and the misalignment played as an external load resulting through the whole driven shaft. The combined effects of disk unbalance and shaft misalignment showed that the misalignment predominated the response in most of the rotation speeds, but the unbalance could become significant at high speed. The whirling orbits before and after the misalignment were illustrated as well, and numerical results showed that the two ends of the misalignment whirled asynchronously as the rotation fell into some regions.

Experimental study and modeling of masonry-infilled concrete frames with and without CFRP jacketing

Huang, Chao-Hsun,Sung, Yu-Chi,Tsai, Chi-Hsin Techno-Press 2006 Structural Engineering and Mechanics, An Int'l Jou Vol.22 No.4

Most existing concrete structures in Taiwan are considered nonductile due to insufficient transverse reinforcement and poor detailing of frame elements. Such features are fairly typical for buildings constructed prior to 1997, at which time the local building code was revised based on ACI 318-95. Among these structures, many contain perimeter or partition walls made of concrete or clay brick for architectural purposes. These walls, though treated as non-structural components in common design practice, could affect the structural behavior of the buildings during an earthquake. To study the behavior of such structures under seismic load, experiments were conducted on concrete frames of various configurations to show the force-deformation relationships, damage patterns, and other characteristics of the frames. For further interest, similar units with columns jacketed by carbon-fiber-reinforced-polymer (CFRP) were also tested to illustrate the effectiveness of this technique in the retrofit of concrete frames.

Echocardiographic parameters and indices in 23 healthy Maltese dogs

Chih-Hung Tsai,Chao-Chun Huang,Chia Chi Ho,Marta Claretti 대한수의학회 2021 Journal of Veterinary Science Vol.22 No.5

Background: Echocardiography is a primary tool used by veterinarians to evaluate heart diseases. In recent years, various studies have targeted standard echocardiographic values for different breeds. Reference data are currently lacking in Maltese dogs and it is important to fill this gap as this breed is predisposed to myxomatous mitral valve disease, which is a volume overload disease. Objectives: To establish the normal echocardiographic parameters for Maltese dogs. Methods: In total, 23 healthy Maltese dogs were involved in this study. Blood pressure measurements, thoracic radiography, and complete transthoracic echocardiography were performed. The effects of body weight, age and sex were evaluated, and the correlations between weight and linear and volumetric dimensions were calculated by regression analysis. Results: The mean vertebral heart size was 9.1 ± 0.4. Aside from the ejection fraction, fractional shortening, and the left atrial to aorta root ratio, all the other echocardiographic parameters were significantly correlated with weight. Conclusion: This study describes normal echocardiographic parameters that may be useful in the echocardiographic evaluation of Maltese dogs.

Interval Type-2 Fuzzy Maximum Power Point Tracking for Solar Photovoltaic Power Charging Systems

Ching-Chih Tsai,Chao-Chun Huang 제어로봇시스템학회 2015 제어로봇시스템학회 국제학술대회 논문집 Vol.2015 No.10

This paper presents an interval type-2 fuzzy maximum power point tracking (IT2FMPPT) control method for a solar photovoltaic (PV) power generation systems with a DC/DC buck converters and a battery charging system. After the brief model descriptions of the solar PV power charging system, the maximum power and its optimal voltage of the system at different illuminations are numerically solved using a Newton-Raphson method. Via the DC/DC buck converter and the current feedback control technique, the proposed MPPT controller is synthesized using PI control and IT2 fuzzy control logics. The asymptotical stability of the overall closed-loop system with the proposed IT2FMPPT controller is investigated in some details. The effectiveness and merit of the proposed IT2FMPPT controller are exemplified by conducting simulations via Matlab/Simulink. Through comparative simulations, the proposed IT2FMPPT controller is shown superior in comparison with a conventional PI MPPT controller and a conventional fuzzy MPPT controller.

Parametric study on a collocated PZT beam vibration absorber and power harvester

Shyh-Chin Huang,Chao-Yang Tsai,Hsiao-Hui Liao 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.11

The parametric effects of a PZT beam that is simultaneously used as a vibration absorber and a power harvester were investigated in this study. A cantilever beam paved with PZT layers and with added tip mass has been widely used as a harvester or sometimes as a Dynamic vibration absorber (DVA). However, the beam is rarely considered a collocated device. In this study, the first step was theoretical derivation of a distributed beam covered with bimorph PZT layers. Then, the beam was attached to a 1DOF vibratory main system. Two indicators for vibration absorption and power harvesting were defined. Numerical results demonstrated that the lumped mass ratio favored both of the abilities, but that the DVA mass ratio influenced these two abilities in exactly the opposite way. The conjunction of a harvester circuit into a DVA shifted its resonance frequency up to 5 % (an extreme case of open circuit R→∞). Simultaneous power harvesting diminished the absorption capability up to 35 % for each set of mass ratios. To achieve the maximum degree of power harvesting, a corresponding load resistance that somewhat increases with the lumped mass ratio is applied. Experimental results verified the existence of the best load resistance, but the measured harvested curve was lower than the theoretical calculation because of structure damping and deviations of PZT material properties.

Material Saving and Product Quality Improvement with the Visualization of Hot Runner Design in Injection Molding

Tzu-Chau Chen,Chao-Tsai Huang,Yan-Chen Chiu,Wei-Da Wang,Cheng-Li Hsu,Chen-Yang Lin,Lung-Wen Kao 한국정밀공학회 2013 International Journal of Precision Engineering and Vol. No.

Runner system plays a very important role in injection molding process. A quality runner design is helpful in improving product qualities and saving material. However, traditional cold runner systems have certain inherent issues. Moreover, poor product cosmetics are commonly seen with the use of traditional cold runners. As a result, hot runner technology has been widely applied. On the other hand, It has been one of the green molding solutions for material/energy saving and clean environments. But the mechanism behind the hot runner system is too complicated to be fully understood. There exist some critical issues currently. As a result, the simulation technolgy is highly needed to examine hot runner designs before the real manufacturing. Through simulation analyses, designers and manufafctuers are able to catch the potential issues on their hot runner systems and revise their designs. Hot runner simulation technology helps with the investigations into the behavior in hot runner system. In this paper, a true 3D numerical method is proposed and applied to investigate the temperature behavior in a real hot runner system for PC material. The experiment is conducted and the simulating result is compared with that from the experiment for the validation purpose.

The tyrosine kinase inhibitor nintedanib activates SHP-1 and induces apoptosis in triple-negative breast cancer cells

Chun-Yu Liu,Tzu-Ting Huang,Pei-Yi Chu,Chun-Teng Huang,Chia-Han Lee,Wan-Lun Wang,Ka-Yi Lau,Wen-Chun Tsai,Tzu-I Chao,Jung-Chen Su,Ming-Huang Chen,Chung-Wai Shiau,Ling-Ming Tseng,Kuen-Feng Chen 생화학분자생물학회 2017 Experimental and molecular medicine Vol.49 No.-

Triple-negative breast cancer (TNBC) remains difficult to treat and urgently needs new therapeutic options. Nintedanib, a multikinase inhibitor, has exhibited efficacy in early clinical trials for HER2-negative breast cancer. In this study, we examined a new molecular mechanism of nintedanib in TNBC. The results demonstrated that nintedanib enhanced TNBC cell apoptosis, which was accompanied by a reduction of p-STAT3 and its downstream proteins. STAT3 overexpression suppressed nintedanib-mediated apoptosis and further increased the activity of purified SHP-1 protein. Moreover, treatment with either a specific inhibitor of SHP-1 or SHP-1-targeted siRNA reduced the apoptotic effects of nintedanib, which validates the role of SHP-1 in nintedanib-mediated apoptosis. Furthermore, nintedanib-induced apoptosis was attenuated in TNBC cells expressing SHP-1 mutants with constantly open conformations, suggesting that the autoinhibitory mechanism of SHP-1 attenuated the effects of nintedanib. Importantly, nintedanib significantly inhibited tumor growth via the SHP-1/p-STAT3 pathway. Clinically, SHP-1 levels were downregulated, whereas p-STAT3 was upregulated in tumor tissues, and SHP-1 transcripts were associated with improved disease-free survival in TNBC patients. Our findings revealed that nintedanib induces TNBC apoptosis by acting as a SHP-1 agonist, suggesting that targeting STAT3 by enhancing SHP-1 expression could be a viable therapeutic strategy against TNBC.