Mechanical Property Determination of a Stereolithographic Resin Subjected to Compressive Loading

Author(s):  
Christian Fry ◽  
Adam Mihalko ◽  
Robert Michael ◽  
Davide Piovesan

This paper presents the findings of destructive compression testing on Formlabs© CLEAR Resin FLGPCL02 and TOUGH Resin FLTOTL03. Compression testing ASTM D695-15 was chosen because of the extreme fragility of the Clear Resin which did not allowed proper tensile testing with our equipment. The material was subjected to a steadily increasing compressive load until complete failure occurred. Five mechanical properties were extracted from stress versus strain curves. The five experimental properties, of Formlabs© CLEAR resin, found were young’s modulus (1.52 GPa) (std = 71 MPa), yield strength (39.6 MPa) (std = 2 MPa), ultimate strength (255 MPa) (std = 35 MPa), strain at fracture (0.509 m/m) (std = 0.0159 m/m), and toughness (49.1 J/m−3) (std = 3.9 J/m−3). The five experimental properties, of Formlabs© TOUGH resin, found were secant modulus (73.9 MPa) (std = 0.87 MPa), yield strength (42.8 MPa) (std = 3.03MPa), ultimate strength (587 MPa) (std = 61 MPa), strain at fracture (0.686 m/m) (std = 0.0097 m/m), and toughness (65 J/m−3) (std = 6 J/m−3). These were then compared to Formlabs© public released values.

2012 ◽  
Vol 256-259 ◽  
pp. 1008-1011
Author(s):  
Yan Mei Zhu ◽  
Shu Cheng Yuan ◽  
Min Hou ◽  
Qing Yuan Wang

This paper presents the experimental results of the wood columns externally strengthened with fiber reinforced polymer (FRP) subjected to axial compressive loading. In total, 14 square short wood columns were made, which were reinforced by FRP in two reinforcing arrangements. The main parameters studied in the test were (1) the strengthening materials, i.e. carbon FRP (CFRP), basalt FRP (BFRP) and aramid FRP (AFRP); (2) the reinforcing arrangements, i.e. the full wrapping of FRP and the partial reinforcing arrangement; (3) the layers of FRP sheets applied, i.e. one, two and three. The ultimate strength, load-axial displacements curves, load-strain relationships, and the failure modes of all the columns were presented. The test results show that both types of the reinforcing arrangements could increase the ultimate strength and stiffness of the columns tested greatly. The columns strengthened with two layers of FRP sheets gave higher load carrying capacities when compared to the columns strengthened with one or three layers of FRP sheets. The result confirms that the more layers of FRP sheets, the higher of load carrying capacity; however, the adverse results were shown when three layers of FRP sheets applied. Finally, the result also showed that the full wrapping reinforcing arrangement is more effective than the partial one in enhancing the stiffness.


2019 ◽  
Vol 9 (10) ◽  
pp. 2088 ◽  
Author(s):  
Chenfeng Li ◽  
Sen Dong ◽  
Tingce Wang ◽  
Weijun Xu ◽  
Xueqian Zhou

The welded stiffened plate is widely used in naval architecture and offshore engineering as a basic structural member. The aim of this study is to investigate the effect of welding residual stress and steel grade on the ultimate strength of stiffened plates under uniaxial compressive load by non-linear finite element analysis. Nineteen stiffened plates built with three types of stiffeners with various column slenderness ratios provided in the ISSC’2000 VI.2 benchmark calculations are employed in the present study. The commercial finite element code ABAQUS is applied to simulate the collapse behavior of the stiffened plates and verified against the benchmark calculations. Fabrication-related imperfections, such as initial deflections and residual stresses, are accounted for in the simulations. The ultimate strength of stiffened plates built in common shipbuilding steels, namely S235, S315, S355 and S390, are investigated by varying the yield strength of materials in the simulation. Analysis of the numerical results shows that the welding residual stress reduces the ultimate strength of stiffened plates, and increase in yield strength of the material can effectively improve the ultimate strength of common ship stiffened plates; and quantitative analyses of their influences have also been performed.


1974 ◽  
Vol 96 (3) ◽  
pp. 839-844 ◽  
Author(s):  
G. F. Weissmann ◽  
B. C. Wonsiewicz

Spring materials are purchased under specifications which impose limits on the tensile strength but do not control the crucial properties, i.e., resistance to plastic flow and stiffness. Present techniques for characterizing spring material are discussed in detail. A novel test is described which is quick, inexpensive, and reliable and holds promise for both research and quality control applications. The test is based on a dynamic determination of energy dissipation in a sample stressed in bending or torsion, the usual modes of deformation for most springs. Stiffness and permissible deformations are determined directly and the elastic modulus and yield strength can be calculated easily. The results obtained in this way compare favorably with those determined by tensile testing. An example is given which illustrates the operation of the test and the calculation of results. Since the entire test from sample preparation to calculation of results requires about five minutes, and since the apparatus should be relatively inexpensive, the test ought to find application in many areas where testing is not practical at the present time.


1993 ◽  
Vol 60 (4) ◽  
pp. 895-902 ◽  
Author(s):  
E. Madenci ◽  
R. A. Westmann

This paper addresses the problem of delamination growth prior to its buckling using mathematical techniques appropriate for mixed boundary value problems. The formulation presented herein does not require buckling as a necessary condition for delamination growth. By employing the stability equations of elasticity theory, solutions to the problem of an infinite layer with a slightly imperfect circular delamination subjected to axisymmetric and uniaxial in-plane compressive loading are presented. This approach permits the determination of the stress intensity factors under specified initial imperfections for applied compressive stress.


2002 ◽  
Vol 27 (4) ◽  
pp. 333-336 ◽  
Author(s):  
B. WANG ◽  
J. B. TANG

We evaluated the effect of length of suture embedment within tendons on the tensile strength of repaired tendons. Thirty fresh pig flexor tendons were divided into three groups and subjected to repairs with the Halsted tendon sutures in which 1/3, 1/2, and 2/3 of the length of the longitudinal sutures was embedded within the tendons. The repaired tendons were pulled to complete failure by an Instron tensile testing machine. The 2 mm gap-formation force, ultimate strength, stiffness, and energy to failure were greatest when 2/3 of the suture length was embedded within the tendon. The results indicate that suture embedment is an important contributor to the tensile properties of the repair, and that increase in length of suture embedment is an effective way to strengthen tendon repairs.


2020 ◽  
Vol 86 (5) ◽  
pp. 43-51
Author(s):  
V. M. Matyunin ◽  
A. Yu. Marchenkov ◽  
N. Abusaif ◽  
P. V. Volkov ◽  
D. A. Zhgut

The history of appearance and the current state of instrumented indentation are briefly described. It is noted that the materials instrumented indentation methods using a pyramid and ball indenters are actively developing and are currently regulated by several Russian and international standards. These standards provide formulas for calculating the Young’s modulus and hardness at maximum indentation load. Instrumented indentation diagrams «load F – displacement α» of a ball indenter for metallic materials were investigated. The special points on the instrumented indentation diagrams «F – α» loading curves in the area of elastic into elastoplastic deformation transition, and in the area of stable elastoplastic deformation are revealed. A loading curve area with the load above which the dF/dα begins to decrease is analyzed. A technique is proposed for converting «F – α» diagrams to «unrestored Brinell hardness HBt – relative unrestored indent depth t/R» diagrams. The elastic and elastoplastic areas of «HBt – t/R» diagrams are described by equations obtained analytically and experimentally. The materials strain hardening parameters during ball indentation in the area of elastoplastic and plastic deformation are proposed. The similarity of «HBt – t/R» indentation diagram with the «stress σ – strain δ» tensile diagrams containing common zones and points is shown. Methods have been developed for determining hardness at the elastic limit, hardness at the yield strength, and hardness at the ultimate strength by instrumented indentation with the equations for their calculation. Experiments on structural materials with different mechanical properties were carried out by instrumented indentation. The values of hardness at the elastic limit, hardness at the yield strength and hardness at the ultimate strength are determined. It is concluded that the correlations between the elastic limit and hardness at the elastic limit, yield strength and hardness at the yield strength, ultimate tensile strength and hardness at the ultimate strength is more justified, since the listed mechanical characteristics are determined by the common special points of indentation diagrams and tensile tests diagrams.


Author(s):  
Sonja Kostic ◽  
Jasmina Miljojkovic ◽  
Goran Simunovic ◽  
Djordje Vukelic ◽  
Branko Tadic

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