Study Regarding the Influence of the Printing Orientation Angle on the Mechanical Behavior of Parts Manufactured by Material Jetting

2021 ◽  
Vol 58 (3) ◽  
pp. 198-209
Author(s):  
Vasile Cojocaru ◽  
Doina Frunzaverde ◽  
Dorian Nedelcu ◽  
Calin-Octavian Miclosina ◽  
Gabriela Marginean

Initially developed as a rapid prototyping tool for project visualization and validation, the recent development of additive manufacturing (AM) technologies has led to the transition from rapid prototyping to rapid manufacturing. As a consequence, increased attention has to be paid to the mechanical, chemical and physical properties of the printed materials. In mechanical engineering, the widespread use of AM technologies requires the optimization of process parameters and material properties in order to obtain components with high, repeatable and time-stable mechanical properties. One of the main problems in this regard is the anisotropic behavior of components made by additive manufacturing, determined by the type of material, the 3D printing technology, the process parameters and the position of the components in the printing space. In this paper the influence of the printing orientation angle on the tensile behavior of specimens made by material jetting is investigated. The aim was to determine if the positioning of components at different angles relative to the X-axis of the printer (and implicitly in relation to the multijet printing head) contributes to anisotropic behavior. The material used was a photopolymer with a mechanical strength between 40 MPa and 55 MPa, according to the producer. Four sets of tensile test specimens were manufactured, using flat build orientation and positioned on the printing table at angles of 0˚, 30˚, 60˚ and 90˚ to the X-axis of the printer. Comparative analysis of the mechanical behavior was carried out by tensile tests and microscopic investigations of the tensile test specimens fracture surfaces.

2010 ◽  
Vol 44-47 ◽  
pp. 2578-2582 ◽  
Author(s):  
Hong Xiao Wang ◽  
Chun Sheng Wang ◽  
Chun Yuan Shi

Recently the problems of resistance spot welding (RSW) stainless steel railway vehicles are causing more attention for poor surface quality. Lap laser welding of stainless steel is investigated with OED(Orthogonal experimental designing ) in this study to replace RSW with the aim of to increase the aesthetics of the car body by eliminating visible indentation on the surface and the flatness of the skin reducing welding deformations. After welding tensile tests and microstructure analysis are performed. The optimization of process parameters were: laser power =2.5kW;welding speed=2.2m/min, focal position=0mm. The fusion zone is symmetrical about the axis of the laser beam and no welding cracks or porosity can be found in any of the welds. This work has great significance of improving the manufacturing level of stainless steel railway vehicles.


2019 ◽  
Vol 9 (6) ◽  
pp. 1256 ◽  
Author(s):  
Amal Charles ◽  
Ahmed Elkaseer ◽  
Lore Thijs ◽  
Veit Hagenmeyer ◽  
Steffen Scholz

Additive manufacturing provides a number of benefits in terms of infinite freedom to design complex parts and reduced lead-times while globally reducing the size of supply chains as it brings all production processes under one roof. However, additive manufacturing (AM) lags far behind conventional manufacturing in terms of surface quality. This proves a hindrance for many companies considering investment in AM. The aim of this work is to investigate the effect of varying process parameters on the resultant roughness of the down-facing surfaces in selective laser melting (SLM). A systematic experimental study was carried out and the effects of the interaction of the different parameters and their effect on the surface roughness (Sa) were analyzed. It was found that the interaction and interdependency between parameters were of greatest significance to the obtainable surface roughness, though their effects vary greatly depending on the applied levels. This behavior was mainly attributed to the difference in energy absorbed by the powder. Predictive process models for optimization of process parameters for minimizing the obtained Sa in 45° and 35° down-facing surface, individually, were achieved with average error percentages of 5% and 6.3%, respectively, however further investigation is still warranted.


Author(s):  
Roy Wang ◽  
Rudolph L. Gleason

Quantifying the mechanical behavior of very soft tissues (VST) is important when studying responses to injury or designing therapeutic devices; fat, brain, or liver being examples of such tissues. VST can have poor suture retention or clamp holding strength, making tensile tests difficult. As a result, uniaxial compression tests are typically the preferred choice to quantify the mechanical behavior. In these tests, isotropy is generally assumed and measuring the deformation in only one direction is needed if the material is considered incompressible [13]. In this study we present a novel testing apparatus for use on VST under uniaxial compression that can detect anisotropic behavior of the tissue if present. We validate the tester using cardiac adipose tissue and isotropic rubber as the control. Understanding the directional behavior of the tissue is important since anisotropy would require testing in multiple directions to fully characterize the material properties.


2018 ◽  
Vol 15 (3) ◽  
pp. 407-413
Author(s):  
Jenarthanan MP ◽  
Prasanna Kumar Reddy Gavireddy ◽  
Chetan Sai Gummadi ◽  
Surya Ramesh Mandapaka

Purpose This paper aims to investigate the effect and parametric optimization of process parameters during milling of glass fibre-reinforced plastics (GFRP) composites using grey relational analysis (GRA). Design/methodology/approach Experiments are conducted using helix angle, spindle speed, feed rate, depth of cut and fibre orientation angle as typical process parameters. GRA is adopted to obtain grey relational grade for the milling process with multiple characteristics, namely, machining force and material removal rate (MRR). Analysis of variance is performed to get the contribution of each parameter on the performance characteristics. Findings It is observed that helix angle and fibre orientation angle are the most significant process parameters that affect the milling of GFRP composites. The experimental results reveal that the helix angle of 45°, spindle speed of 3000 rpm, feed rate of 1000 mm/min, depth of cut of 2 mm and fibre orientation angle of 15° is the optimum combination of lower machining force and higher MRR. The experimental results for the optimal setting show that there is considerable improvement in the process. Originality/value Optimization of process parameters on machining force and MRR during endmilling of GFRP composites using GRA has not been attempted previously.


2015 ◽  
Vol 22 (1) ◽  
pp. 127-138 ◽  
Author(s):  
Stanisław Adamczak ◽  
Jerzy Bochnia ◽  
Bożena Kaczmarska

AbstractThe aim of this study was to assess the innovation risk for an additive manufacturing process. The analysis was based on the results of static tensile tests obtained for specimens made of photocured resin. The assessment involved analyzing the measurement uncertainty by applying the FMEA method. The structure of the causes and effects of the discrepancies was illustrated using the Ishikawa diagram. The risk priority numbers were calculated. The uncertainty of the tensile test measurement was determined for three printing orientations. The results suggest that the material used to fabricate the tensile specimens shows clear anisotropy of the properties in relation to the printing direction.


2015 ◽  
Vol 29 (06n07) ◽  
pp. 1540011 ◽  
Author(s):  
Shih-Hsuan Chiu ◽  
Cheng-Chin Chen ◽  
Kun-Ting Chen ◽  
Chun-Hao Su

Rapid prototyping (RP) technologies have been extensively applied to build products in recent decades. The area-forming rapid prototyping is an emerging RP technology with the advantages of a simple procedure with a short processing time. With the expansion in fields of application, the strictness on product quality has also increased. The dimensional accuracy of a product is one of the most critical quality characteristics. In order to improve the dimensional accuracy of a product from an area-forming RP system, this study optimizes the seven factors via the Taguchi method, and the result is verified with an extra sample.


2006 ◽  
Vol 116-117 ◽  
pp. 259-262 ◽  
Author(s):  
Hee Jong Lee ◽  
Jung Han Song ◽  
Hoon Huh

This paper is concerned with the thermo-mechanical behavior of steel sheet for an autobody including the temperature dependent strain-rate sensitivity. Tensile tests have been carried out with the high strength steel sheets such as SPRC35R, SPRC45E and TRIP60. The tensile tests were performed with the variation of the strain-rates from 0.001/s to 200/s and with the variation of environmental temperatures from -40 to 200. The thermo-mechanical response at the quasi-static state is obtained with the static tensile test and the one at the intermediate strain-rate is obtained with the high speed tensile test. Both the strain-rate and the temperature sensitivity of the flow stress are calculated for the quantitative evaluation of thermo-mechanical behavior of steel sheets. The results demonstrate that as the strain-rate increases, the variation of the flow stress becomes more dependent on the temperature. The results also indicate that the material properties of SPRC35R are more sensitive to the strain-rate and the temperature than those of SPRC45E and TRIP60.


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