Vibratory System Identification of 3D Printed Cantilever

2018 ◽  
Author(s):  
Daniel Crifasi ◽  
Matthew Ergle ◽  
Hüseyin Özdeş ◽  
Edmon Perkins
Keyword(s):  
Carbon Fiber ◽  
3D Printing ◽  
Natural Frequency ◽  
High Speed ◽  
Damping Ratio ◽  
Thermoplastic Composites ◽  
Vibratory System ◽  
Vibratory Response ◽  
3D Printed ◽  
Materials Used

Although 3D printing has become a widespread method of fabrication, the vibratory properties of thermoplastic composites are poorly understood. This is, in part, due to the anisotropies introduced by the 3D printing process, the composite materials used, and the geometry. In this study, an attempt has been made to characterize the vibratory response of a 3D printed thermoplastic cantilever, in order to determine the damping ratio and natural frequency. The cantilevered beams were 3D printed, with a range of varied parameters. These parameters include the inclusion and exclusion of continuous carbon fiber reinforcement, as well as the three orthogonal build directions. Impact tests and frequency sweeps were used to gain information about the vibratory response of these cantilevers. This information was used to model the effects of the carbon fiber and anisotropy introduced by the different build parameters. During the experiments, a high-speed camera was used to record the response of the cantilevers. These videos were then post-processed with image analysis tools to quantify the response. Then, a point near the tip of the cantilever was used as the time-dependent variable for a reduced order model. By proceeding in this described method, the damping ratio and natural frequency of the system may be written as a function of the build parameters.

scholarly journals DESIGN OF A 3D-PRINTED THREE-CLAW ROBOTIC GRIPPER END-EFFECTOR

2021 ◽  
Vol 11 (4) ◽  
pp. 70-79
Author(s):  
Dino Dominic Forte Ligutan ◽  
Argel Alejandro Bandala ◽  
Jason Limon Española ◽  
Richard Josiah Calayag Tan Ai ◽  
Ryan Rhay Ponce Vicerra ◽  
...  
Keyword(s):  
3D Printing ◽  
Polylactic Acid ◽  
Grip Force ◽  
Thermoplastic Polyurethane ◽  
Robotic Arm ◽  
End Effector ◽  
Design Considerations ◽  
3D Printed ◽  
Materials Used ◽  
Metal Work

The development of a novel 3D-printed three-claw robotic gripper shall be described in this paper with the goal of incorporating various design considerations. Such considerations include the grip reliability and stability, grip force maximization, wide object grasping capability. Modularization of its components is another consideration that allows its parts to be easily machined and reusable. The design was realized by 3D printing using a combination of tough polylactic acid (PLA) material and thermoplastic polyurethane (TPU) material. In practice, additional tolerances were also considered for 3D printing of materials to compensate for possible expansion or shrinkage of the materials used to achieve the required functionality. The aim of the study is to explore the design and eventually deploy the three-claw robotic gripper to an actual robotic arm once its metal work fabrication is finished.

3D printing of biofiber-reinforced composites and their mechanical properties: a review

2020 ◽  
Vol 26 (6) ◽  
pp. 1113-1129
Author(s):  
Lai Jiang ◽  
Xiaobo Peng ◽  
Daniel Walczyk
Keyword(s):  
Mechanical Properties ◽  
3D Printing ◽  
Reinforced Composites ◽  
Research Directions ◽  
Content Type ◽  
Reinforced Composite ◽  
3D Printed ◽  
Materials Used ◽  
Printing Processes ◽  
Pure Resin

Purpose This paper aims to summarize the up-to-date research performed on combinations of various biofibers and resin systems used in different three-dimensional (3D) printing technologies, including powder-based, material extrusion, solid-sheet and liquid-based systems. Detailed information about each process, including materials used and process design, are described, with the resultant products’ mechanical properties compared with those of 3D-printed parts produced from pure resin or different material combinations. In most processes introduced in this paper, biofibers are beneficial in improving the mechanical properties of 3D-printed parts and the biodegradability of the parts made using these green materials is also greatly improved. However, research on 3D printing of biofiber-reinforced composites is still far from complete, and there are still many further studies and research areas that could be explored in the future. Design/methodology/approach The paper starts with an overview of the current scenario of the composite manufacturing industry and then the problems of advanced composite materials are pointed out, followed by an introduction of biocomposites. The main body of the paper covers literature reviews of recently emerged 3D printing technologies that were applied to biofiber-reinforced composite materials. This part is classified into subsections based on the form of the starting materials used in the 3D printing process. A comprehensive conclusion is drawn at the end of the paper summarizing the findings by the authors. Findings Most of the biofiber-reinforced 3D-printed products exhibited improved mechanical properties than products printed using pure resin, indicating that biofibers are good replacements for synthetic ones. However, synthetic fibers are far from being completely replaced by biofibers due to several of their disadvantages including higher moisture absorbance, lower thermal stability and mechanical properties. Many studies are being performed to solve these problems, yet there are still some 3D printing technologies in which research concerning biofiber-reinforced composite parts is quite limited. This paper unveils potential research directions that would further develop 3D printing in a sustainable manner. Originality/value This paper is a summary of attempts to use biofibers as reinforcements together with different resin systems as the starting material for 3D printing processes, and most of the currently available 3D printing techniques are included herein. All of these attempts are solutions to some principal problems with current 3D printing processes such as the limit in the variety of materials and the poor mechanical performance of 3D printed parts. Various types of biofibers are involved in these studies. This paper unveils potential research directions that would further widen the use of biofibers in 3D printing in a sustainable manner.

scholarly journals The Application of 3D-Printing Techniques in the Manufacturing of Cement-Based Construction Products and Experiences Based on the Assessment of Such Products

Buildings ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 144
Author(s):  
Guillermo Sotorrío Ortega ◽  
Javier Alonso Madrid ◽  
Nils O. E. Olsson ◽  
José Antonio Tenorio Ríos
Keyword(s):  
3D Printing ◽  
Construction Industry ◽  
Material Consumption ◽  
Construction Products ◽  
International Projects ◽  
Substantial Progress ◽  
3D Printed ◽  
Materials Used ◽  
Printing Techniques

The construction industry has embraced digitisation and industrialisation in response to the need to increase its productivity, optimise material consumption and improve workmanship. Additive manufacturing (AM), more widely known as 3D printing, has driven substantial progress in these respects in other industries, and a number of national and international projects have helped to introduce the technique to the construction industry. As with other innovative processes not covered by uniform standards, appropriate assessments and testing methodologies to control the quality of the 3D-printed end products, while not obligatory, are advisable. This article shows that regulation is not an obstacle to the use of an innovative product, such as 3D printing, by proposing quality-control tests and an assessment methodology, in the understanding that standardisation ensures the viability of a technology. The information, including the methods and results, is based on the authors’ experiences in the development of three research projects pertaining to 3D printing. This paper also discusses whether the performance of the materials used in 3D printing could be superior to traditional ones.

The Effects of Fiber Volume Fraction on the Experiment Modal Behavior of 30°/-60° Carbon Fiber Plain Woven Fabric / Epoxy Resin Composites

2011 ◽  
Vol 331 ◽  
pp. 175-178
Author(s):  
Xiao Yuan Pei ◽  
Jia Lu Li
Keyword(s):  
Carbon Fiber ◽  
Epoxy Resin ◽  
Natural Frequency ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Laminated Composites ◽  
Damping Ratio ◽  
Test Method ◽  
Woven Fabric ◽  
Fiber Volume

A study on dynamic mechanical properties of carbon fiber plain woven fabric (with fiber orientation of 30°/-60°) / epoxy resin laminated composites with different fiber volume fraction was carried out. The test method is single input single output free vibration of cantilever beam hammering modal analysis method. The effect of different fiber volume fraction on the modal parameters of laminated composites was analyzed. The experimental results show that with the fiber volume fraction increasing, the natural frequency of laminated composites becomes larger and damping ratio becomes smaller. The fiber volume fraction is greater, the peak value of natural frequency becomes higher and the attenuating degree of acceleration’ amplitude becomes slower.

Hydrostatic Gas Journal Bearings for Micro-Turbomachinery

2004 ◽  
Vol 127 (2) ◽  
pp. 157-164 ◽  
Author(s):  
L. X. Liu ◽  
C. J. Teo ◽  
A. H. Epstein ◽  
Z. S. Spakovszky
Keyword(s):  
Natural Frequency ◽  
Analytical Model ◽  
High Speed ◽  
Experimental Testing ◽  
Fluid Dynamic ◽  
Damping Ratio ◽  
Journal Bearings ◽  
Fiber Optic Sensor ◽  
Gas Bearings ◽  
Aspect Ratios

Several years ago an effort was undertaken at MIT to develop high-speed rotating MEMS (Micro Electro-Mechanical Systems) using computer chip fabrication technology. To enable high-power density the micro-turbomachinery must be run at tip speeds of order 500m∕s, comparable to conventional scale turbomachinery. The high rotating speeds (of order 2 million rpm), the relatively low bearing aspect ratios (L∕D<0.1) due to fabrication constraints, and the laminar flow regime in the bearing gap place the micro-bearing designs to an exotic spot in the design space for hydrostatic gas bearings. This paper presents a new analytical model for axially fed gas journal bearings and reports the experimental testing of micro gas bearings to characterize and to investigate their rotordynamic behavior. The analytical model is capable of dealing with all the elements of, (1) micro-devices, (2) dynamic response characteristics of hydrostatic gas bearings, (3) evaluation of stiffness, natural frequency and damping, (4) evaluation of instability boundaries, and (5) evaluation of effects of imbalance and bearing anisotropy. First, a newly developed analytical model for hydrostatic gas journal bearings is introduced. The model consists of two parts, a fluid dynamic model for axially fed gas journal bearings and a rotordynamic model for micro-devices. Next, the model is used to predict the natural frequency, damping ratio and the instability boundary for the test devices. Experiments are conducted using a high-resolution fiber optic sensor to measure rotor speed, and a data reduction scheme is implemented to obtain imbalance-driven whirl response curves. The model predictions are validated against experimental data and show good agreement with the measured natural frequencies and damping ratios. Last, the new model is successfully used to establish bearing operating protocols and guidelines for high-speed operation.

scholarly journals Tensile-test-Property Evaluations of 3D Printed Continuous Carbon Fiber Reinforced Thermoplastic Composites

2019 ◽  
Vol 45 (4) ◽  
pp. 141-148
Author(s):  
Akira TODOROKI ◽  
Tatsuki OASADA ◽  
Yoshihiro MIZUTANI ◽  
Yoshiro SUZUKI ◽  
Masahito UEDA ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Tensile Test ◽  
Thermoplastic Composites ◽  
Fiber Reinforced ◽  
Continuous Carbon Fiber ◽  
3D Printed ◽  
Carbon Fiber Reinforced

scholarly journals Parameters Affecting the Mechanical Properties of Three-Dimensional (3D) Printed Carbon Fiber-Reinforced Polylactide Composites

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2456
Author(s):  
Demei Lee ◽  
Guan-Yu Wu
Keyword(s):  
Mechanical Properties ◽  
Carbon Fiber ◽  
3D Printing ◽  
Three Dimensional ◽  
Fused Deposition Modelling ◽  
Layer By Layer ◽  
Fused Deposition ◽  
Bed Temperature ◽  
3D Printed ◽  
The Impact

Three-dimensional (3D) printing is a manufacturing technology which creates three-dimensional objects layer-by-layer or drop-by-drop with minimal material waste. Despite the fact that 3D printing is a versatile and adaptable process and has advantages in establishing complex and net-shaped structures over conventional manufacturing methods, the challenge remains in identifying the optimal parameters for the 3D printing process. This study investigated the influence of processing parameters on the mechanical properties of Fused Deposition Modelling (FDM)-printed carbon fiber-filled polylactide (CFR-PLA) composites by employing an orthogonal array model. After printing, the tensile and impact strengths of the printed composites were measured, and the effects of different parameters on these strengths were examined. The experimental results indicate that 3D-printed CFR-PLA showed a rougher surface morphology than virgin PLA. For the variables selected in this analysis, bed temperature was identified as the most influential parameter on the tensile strength of CFR-PLA-printed parts, while bed temperature and print orientation were the key parameters affecting the impact strengths of printed composites. The 45° orientation printed parts also showed superior mechanical strengths than the 90° printed parts.

Influence of different materials used for 3D printing in miniature speaker enclosure development

2021 ◽  
Vol 263 (1) ◽  
pp. 5631-5636
Author(s):  
Bartlomiej Chojnacki ◽  
Jan Pawlik ◽  
Tadeusz Kamisinski
Keyword(s):  
3D Printing ◽  
Manufacturing Industry ◽  
Technology Development ◽  
Detailed Comparison ◽  
Rigid Plastic ◽  
Current State ◽  
3D Printed ◽  
Manufacturing Techniques ◽  
Complicated Geometry ◽  
Materials Used

Additive manufacturing techniques are commonly used in industry and mechanical prototyping. The past years brought rapid growth in this technology development, also in the speaker cabinets manufacturing industry. We observe numerous DIY projects on the market based on the 3D printed cabinet parts; however, this technology also offers novel options that should be investigated and documented. In the current state of the art, the basic properties and construction aspects for speaker acoustic performance is not provided as the 3d printing technique is usually treated as the tool for other projects' development. This paper will provide a detailed comparison of the most common 3D printing materials used in FDM techno9logy, such as PLA, TPE, PET-G, and others with different mechanical properties. Example enclosure for a loudspeaker of 37 mm diameter will be printed in different shapes and compared for frequency and sensitivity differences. The results will be discussed, investigating the possible use of different than traditional rigid plastic enclosures and new options using complicated geometry shapes possibly to manufacture with 3D printing techniques.

The Effects of Fiber Orientation on the Vibration Modal Behavior of Carbon Fiber Plain Woven Fabric/Epoxy Resin Composites

2011 ◽  
Vol 391-392 ◽  
pp. 345-348 ◽  
Author(s):  
Xiao Yuan Pei ◽  
Jia Lu Li
Keyword(s):  
Carbon Fiber ◽  
Epoxy Resin ◽  
Natural Frequency ◽  
Fiber Orientation ◽  
Volume Fraction ◽  
Damping Ratio ◽  
Woven Fabric ◽  
Resin Composites ◽  
Fiber Volume ◽  
Epoxy Resin Composites

The modal properties of carbon fiber woven fabric / epoxy resin composites with different fiber orientation angles were studied by using single input single output free vibration of cantilever beam hammering modal analysis method. With the same fiber volume fraction, the different fiber orientation of the laminated composite has an effect on parameters of vibration mode of composites. The experimental results show that with the fiber orientation increasing, the natural frequency of laminated composites becomes smaller and damping ratio becomes larger. The fiber orientation smaller, the peak value of natural frequency becomes higher and the attenuating degree of acceleration amplitude becomes slower.

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