Tensile Strength Of Specimens Research Articles

Experimental study on the deterioration of mechanical properties of sandy mudstone under different water-gas interactions

Based on the water-rock-gas coupling test system, the work combined the scanning electron microscope and XTDIC 3D full-field strain measurement system. The Brazilian splitting test was performed on four groups of sandy mudstone specimens under contrast (CO), mash-gas soaking (MS), water-mash gas soaking (WM), and water-soaking (WS) conditions. The tensile strength, deformation failure, and microscopic characteristics of fractures were studied to reveal the deterioration mechanism of the tensile properties of sandy mudstone under water-gas coupling. The results showed that the uniaxial tensile strength of sandy mudstone specimens under the three soaking conditions was less than that of the contrast conditions. Compared with specimens in the CO group, the tensile strength of specimens in MS-WS groups was reduced; the WS group decreased the most. Specimens changed from brittle failure to plastic failure after soaking. The decrease rate in strength after the peak was consistent with the change trend in tensile strength. It led to a larger localized deformation zone of specimens and more obvious displacement. The deformation localization zone of the WS group was the broadest, with the most intense displacement. Besides, stress concentration first occurred in the submerged part of the WM group. Fractures expanded in the direction of maximum principal strain. The internal pore structure of sandy mudstone specimens in each group changed after soaking. The average porosity, maximum pore area, and probability entropy of specimens in WS-MS groups increased compared to the CO group. The WS group had the largest reduction and the MS group had the smallest. The pre-peak energy storage capacity of sandy mudstone specimens was gradually weakened. Compared with the CO group, that in the WS-MS groups was reduced. The WS group had the greatest reduction, and the MS group had the smallest. The deterioration effect of water on the interior of sandy mudstone was stronger than that of gas. The work is of great significance for understanding the stability of coal and rocks in closed-pit high-gas mines.

Experimental Study of Performance of Ti-6Al-4V Femoral Implants Using Selective Laser Melting (SLM) Methodology

Selective laser melting (SLM) technology used for the design and production of porous implants can successfully address the issues of stress shielding and aseptic loosening associated with the use of solid implants in the human body. In this paper, orthogonal experiments were used to optimize the process parameters for SLM molding of Ti-6Al-4V (TC4) material to investigate the effects of the process parameters on the densities, microscopic morphology, and roughness, and to determine the optimal process parameters using the roughness as a judging criterion. Based on the optimized process parameters, the mechanical properties of SLM-formed TC4 alloy specimens are investigated experimentally in this paper. The main conclusions are as follows: the optimal combination of roughness is obtained by polar analysis, the microhardness of SLM-molded TC4 alloy molded specimens is more uniform, the microhardness of specimens on the side and the front as well as the abrasion resistance is higher than that of casting specimens, the yield strength and tensile strength of specimens is higher than that of ASTM F136 standard and casting standard but the elongation is not as good as that of the standard, and the elasticity and compressive strength of porous specimens are higher than that of casting specimens at different volume fractions. The modulus of elasticity and compressive strength are within the range of human skeletal requirements. This work makes it possible to fabricate high-performance porous femoral joint implants from TC4 alloy SLM-molded materials.

Influence of Petroleum-Based and Bio-Derived Recycling Agents on High-RAP Asphalt Mixtures Performance

Reclaimed asphalt pavement (RAP) has been utilized as a potential partial substitute for virgin asphalt binder in asphalt mixtures. However, a primary concern with increasing RAP content in asphalt mixtures is the cracking potential, attributed to the aged RAP asphalt binder (RAP-binder). To address this, the use of petroleum-based and bio-derived recycling agents (RAs) in enhancing the cracking resistance of high-RAP asphalt mixtures has been explored. The objective of this study is to ascertain the effectiveness of six RAs in mitigating cracking in high-RAP asphalt mixtures. The RAs considered include petroleum-crude-oil-derived aromatic oil, soy oil, and four types of tall-oil-derived phytosterol (industrial by-product, intermediate, purified, and fatty acid-based). The RAs’ dosages were optimized, based on RAP-binder and unmodified asphalt binder properties, to produce target PG 70-22 asphalt binder when incorporated in asphalt mixtures containing 30% RAP. To assess the engineering performance of these 30%-RAP asphalt mixtures for each RA, a conventional asphalt mixture incorporating styrene-butadiene-styrene (SBS)-modified PG 70-22 asphalt binder without RAP or RAs was benchmarked for comparison. Mechanical tests performed included Hamburg wheel-track testing (HWTT), intermediate-temperature fracture tests (semi-circular bend, Illinois flexibility index, and IDEAL cracking tolerance), and thermal stress-restrained specimen tensile strength test to evaluate permanent deformation, intermediate-temperature cracking resistance, and low-temperature cracking resistance, respectively. Results showed that petroleum-crude-oil-derived aromatic oil and tall-oil-derived fatty-acid-based oil RAs were able to rejuvenate RAP-binder as measured by the cracking tests performed. Further, the use of these RAs did not adversely impact the asphalt mixtures’ permanent deformation performance.

The study of screw extrusion-based additive manufacturing of eco-friendly aliphatic polyketone

Aliphatic polyketone is a new-age eco-friendly, high-performance engineering thermoplastic. However, its potential for replacing other polymers depends on its ability to be processed. Considering that the first aliphatic polyketone suitable for processing was developed relatively recently (2015), the material gained new research potential. In this paper screw extrusion-based process was developed for additive manufacturing of aliphatic polyketone. A detailed characterisation of the process and printed samples was done. It was shown that the extruder-base process can produce stable additive-manufactured parts depending on printing speed (process parameters). The interpass temperature has a significant influence on printing properties and it depends on printing speed (travel speed of building platform and extruder rotational speed). With the increase in the printing speed, the interpass temperature increases as well. If it is low causes insufficient heat for diffusion to occur causing delamination and if it is too high causes geometrical deviation of workpieces which leads to defects causing a reduction in inter-road strength. The tensile strength of specimens with raster angle 0° was 62.7 ± 1.4 MPa, which is slightly higher than the tensile strength of base material guaranteed by the supplier (60 MPa) while the elongation up to the first crack was 32.8 ± 4.6%. Iinter-road strength in specimens with a raster angle of 90° was 37.2 ± 0.8 MPa which is 62% of the base material while interpass temperature was 189 ± 3.3 °C.

Machine learning-based prediction of preplaced aggregate concrete characteristics

Preplaced-Aggregate Concrete (PAC) is a type of preplaced concrete where coarse aggregate is placed in the mold and a Portland cement-sand grout with admixtures is injected to fill the voids. Due to the complex nature of PAC, many studies were conducted to determine the effects of admixtures and the compressive and tensile strengths of PAC. Considering that a prediction tool is needed to estimate the compressive and tensile strengths of PAC, this research developed 12 supervised Machine Learning (ML) algorithms in Python software to provide estimations for civil engineers. To prepare the training and testing datasets, a comprehensive investigation was performed to prepare experimental studies on the compressive and tensile strengths of PAC. Then, according to the features of the dataset, four scenarios were defined based on the input features. The capability of ML algorithms was investigated in each scenario. Results showed that the ETR, RDF, and BR algorithms achieved the prediction accuracy of 98.3%, 95.3% and 94.6%, respectively, for estimating the compressive strength of PAC with input features of Case B. Therefore, due to the performance of the ML models, their generality was investigated by preparing the experimental test of two specimens of PAC and by validating the results. Notably, that the proposed ML models (e.g. BR method) can accurately predict the compressive and tensile strengths of specimens (e.g. with accuracy of 98.4 ∼ 99.7%, respectively) and can be used to facilitate and reduce the experimental tests as well as the experimental efforts.

Investigating the Fracture Process and Tensile Mechanical Behaviours of Brittle Materials under Concentrated and Distributed Boundary Conditions

In this study, concrete was selected to investigate the real-time splitting tensile mechanical and fracture behaviours of brittle materials using the Brazilian test under concentrated and distributed boundary conditions. The digital image correlation (DIC) method was adopted to evaluate the tensile strength and failure process in Brazilian tests using a high-resolution camera. The DIC results showed that the position of the crack initiation randomly occurred at the centre of a disc and at the boundary in Brazilian tests with concentrated loads (BTC). Comparatively, the crack initiated at the centre of discs in most Brazilian tests with distributed loads (BTD), as validated by the DIC results. Our results indicated that the average nominal tensile strength of specimens cracking at the boundary was larger than that of specimens cracking at the centre in the BTC, suggesting that the nominal tensile strength measured by the Brazilian test was related to the failure process of the discs. Moreover, this study demonstrated that the tensile strength measured by the Brazilian test was dependent on the boundary conditions. The equation recommended by the ISRM (International Society for Rock Mechanics) might slightly overestimate the tensile strength of brittle materials based on the pure elastic theory and hyperbolic-distributed loading conditions at the boundaries.

Study on 3D printing process of continuous polyglycolic acid fiber-reinforced polylactic acid degradable composites.

A continuous polyglycolic acid (PGA) fiber-reinforced polylactic acid (PLA) degradable composite was proposed for application in biodegradable load-bearing bone implant. The fused deposition modeling (FDM) process was used to fabricate composite specimens. The influences of the printing process parameters, such as layer thickness, printing spacing, printing speed, and filament feeding speed on the mechanical properties of the PGA fiber-reinforced PLA composites, were studied. The thermal properties of the PGA fiber and PLA matrix were investigated by using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The internal defects of the as-fabricated specimens were characterized by the micro-X- ray 3D imaging system. During the tensile experiment, a full-field strain measurement system was used to detect the strain map and analysis the fracture mode of the specimens. A digital microscope and field emission electron scanning microscopy were used to observe the interface bonding between fiber and matrix and fracture morphologies of the specimens. The experimental results showed that the tensile strength of specimens was related to their fiber content and porosity. The printing layer thickness and printing spacing had significant impacts on the fiber content. The printing speed did not affect the fiber content but had a slight effect on the tensile strength. Reducing the printing spacing and layer thickness could increase the fiber content. The tensile strength (along the fiber direction) of the specimen with 77.8% fiber content and 1.82% porosity was the highest, reaching 209.32 ± 8.37 MPa, which is higher than the tensile strength of the cortical bone and polyether ether ketone (PEEK), indicating that the continuous PGA fiber-reinforced PLA composite has great potential in the manufacture of biodegradable load-bearing bone implants.

Observation of fracture process zone and produced fracture surface roughness in granite under Brazilian splitting tests

In many rock engineering structures, the fracture network's complexity and the generated fractures' roughness are immensely important for understanding the hydraulic conductivity of the rock mass. Despite significant progress, the mechanisms governing nucleation and growth of fracture process zone (FPZ) are still debated. The present work investigates the characteristics of the FPZ and the surface roughness of the produced fracture in granite under tensile loading at two different loading rates. Acoustic emission (AE) and digital image correlation (DIC) techniques were simultaneously employed to monitor the development of the FPZ in disc specimens of granite subjected to Brazilian splitting tests. In addition, several roughness parameters of the produced fractures were measured, and it was tried to link the locations and the magnitudes of the AE events with the height distribution of the fracture surface. Our results indicated that the loading rate significantly influences the extent of the FPZ. The tensile strength of specimens also increased with the loading rate. The FPZ estimated from the AE and DIC data were in good agreement; however, AE provided a slightly wider process zone for all specimens, regardless of the loading rate. It was observed that reducing the loading rate led to a larger FPZ and generated macroscopic fractures with higher roughness characteristics. Moment tensor inversion of the AE signals revealed that in all tested specimens, macroscopic fractures, which are conventionally considered tensile fractures, are composed of three main cracking mechanisms at the microscale, including tensile, shear, and compressive sources. Focal mechanisms distribution showed that the cracks might initiate under tensile, shear, or a combination of both mechanisms. This study’s findings can help in better understanding the rock fracturing processes under tensile loading in granitic rocks for field applications.

Effect of geogrid reinforcement on tensile failure of high-strength self-compacted concrete

In this study, the tensile strength, failure mechanism and ductile behaviour of geogrid-reinforced high-strength self-compacting concrete discs subjected to both the Brazilian tensile strength test and a biaxial compressive test are studied. To determine the combined effects of geogrid layer numbers and inclination angle on the ultimate tensile strength of concrete samples, 21 experiments were conducted with up to three layers of geogrids inclined at angles of 0° to 90°, at increments of 15°. In addition, discrete-element numerical simulations were conducted using two-dimensional particle flow code to examine the failure behaviour of geogrid-reinforced high-strength self-compacting concrete discs. The numerical models were first calibrated by the experimental results and then the failure behaviour of models containing geogrids was investigated. Both experimental and numerical results demonstrate that augmenting the concrete discs with geogrids increases the ductility of specimens, especially after failure. As the number of geogrid layers increased, the tensile strength of specimens also increased, whereas the tensile strength and absorbed energy were the same for specimens with different numbers of geogrid layers and inclination angles of 75° and 90°. The specimen with three horizontal geogrid layers had the highest tensile strength, biaxial compression strength and ductility of all specimens tested.

A Statistical Analysis on Tensile behaviour of Single Edge Notched Jute Hybrid Composites

In this work, a statistical model was developed using Taguchi technique to study the factors influencing the tensile strength of single edge notched jute hybrid composites. Standard uniaxial tensile tests were conducted to evaluate tensile strength of single edge notched jute hybrid composite specimens, with different fiber orientations, glass volume fractions and notch sizes, in accordance with ASTM D3039 standards. It is observed that as glass volume fraction increases, tensile strength increases. As notch size increases, tensile strength decreases. The tensile strengths of specimens in fiber direction (0°/90°) were higher than those in off fiber direction (±45°). The forecast model indicates that the major parameters that impact the tensile strength were glass volume fraction and fiber orientation. Notch size had lesser impact on tensile strength. The optimum value of the tensile strength is observed for specimen with 0/90 fiber orientation, 45% glass volume fraction, 2mm notch size and from the confirmation test, the model results were observed to be near to the experimental values.

Uniaxial tensile response of basalt fiber with different structures reinforced fine-grained concrete via acoustic emission monitoring

Uniaxial tensile behaviors of basalt fiber and basalt textile reinforced fine-grained concrete composites under the same fiber volume content with different curing cycles (7 days, 14 days, 21 days and 28 days) were investigated using acoustic emission technology (AE), specifically, including three types of basalt fibers (0.34%, 0.68% and 1.02%) and basalt textiles (1, 2 and 3). The results indicated that the tensile strength of specimens was positively correlated with the curing cycles. As the volume content of basalt fiber increased, the reinforcing effect on fine-grained concrete was improved. The Aveton-Cooper-Kelly (ACK) model was the starting point for analyzing the reinforcement mechanism of basalt textiles. Compared with basalt fibers, basalt textiles could significantly improve the cracking load, ultimate load, cracking displacement and ultimate displacement of fine-grained concrete. The specimens had obvious characteristics of strain hardening during the entire fracture process. The AE signals had a high correlation with the the load-displacement curves during entire experimental process. AE signals were classified to illustrate different fracture mechanisms: textiles slipping, textiles pulling out, matrix-textiles debonding and textiles breaking. AE technology was comprehensively used for the first time to compare and describe the uniaxial tensile properties of basalt fibers and basalt textiles reinforced fine-grained concrete composites.

Study of Mechanical Properties on Ferric Oxide Microparticles Reinforced with Polyethylene

Polyethylene and ferric oxide microparticles were mixed in this work to generate a new polymer composite. Weight fraction and microparticle size were studied experimentally to discover how they influenced the tensile strength and Young’s modulus. A response surface methodology was employed in the design of the research. The increased weight fraction of reinforcement results in the increase in Young’s modulus and lowers the elongation percentage. As the microparticles expanded in size, so did their effect on the composite’s mechanical characteristics. The tensile strength of specimens containing 20% ferric oxide and particle size of more than 91 µm was dropped by 18 percent due to the agglomeration of microparticles. The addition of 24% Fe2O3 microparticles smaller than 33 μm raised Young’s modulus and tensile strength by 340 percent and 65 percent, respectively.

Thermal degradation behavior of flame-resistant fabrics exposed to fires: effect of air gap type and thickness

The thermal degradation of flame-resistant fabrics reduces the protective ability of clothing and affects firefighters’ safety. Making clear the influence factors of fabric thermal degradation is important for predicting and prolonging the service life of fire-protection clothing. Experiments were conducted for open and sealed air gaps with different thicknesses under flame exposure. The degradation the of outer shell fabric was evaluated by observing the variation in fabric morphology, mass loss and tensile strength of specimens after heat exposure. The influence mechanism of the type and thickness of the air gap on thermal degradation was analyzed by the surface temperature curve and thermal stability of the fabric, as well as the microstructure of the fiber. The results indicated that the type and thickness of the air gap have a significant effect on thermal degradation, and a more serious negative effect was observed under the condition of an open air gap. After being exposed to heat fluxes of 30 and 50 kW/m2 for 40 s, the mass loss rates were 1.8% and 3.3% higher than those of the sealed air gap, and the tensile strength retention rates were 9.1% and 10.1% lower on average, respectively. Air gap type and thickness affected the heat storage and heat transfer efficiency in the fabric system by changing the heat transfer mode. The decomposition and fracture of the fabric were affected, which made the flame-resistant fabrics show different degrees of thermal degradation.

Effect of expanded polystyrene beads on the properties of foam concrete containing polypropylene fiber

In this study, foam concrete was produced using 3 different volumes of EPS beads (up to 100%), 3 different volumes of polypropylene(PP) fiber (up to 0.1)%, sand and 40% pre-produced foam which is fixed by volume. The water-cement ratio was 0.4 and the sand-cement ratio was chosen as 1. The foam concrete were cast into molds with a size of 100 x 100 x 500 mm and 150 x 150 x 150 mm prism. Unit weight, ultrasonic pulse, water absorption, splitting tensile strength, bending strength and compressive strength tests were achieved. Foam concrete were kept in laboratory standard conditions. According to the results of study, unit weight and ultrasonic pulse velocity vary between 970-1350 kg/m3 and 1.6-2.6 km/sec, respectively. The water absorption of the foam concrete decreased up to 65% as the EPS beads ratio increased. Since EPS beads do not contribute to the strength and act like a void, splitting tensile strength in specimens containing EPS beads decreased by up to 70%. The use of fiber contributes to the splitting tensile strength, especially in specimens that do not contain EPS beads, and it increased the strength by 78%. Similarly, the flexural strength of the PP fiber addition increased by up to 70%. As the EPS beads ratio increased, the flexural strengths decreased by 77%. With the addition of PP fiber, the compressive strength increased by 55%. However, since EPS beads' strength is negligible, it caused a 60% decrease in compressive strength.

The Influence of Tensile Strength Difference with Variable Gravel Sizes on the Hydraulic Fracture Propagation in the Conglomerate Reservoir

Conglomerate reservoir is a representative reservoir of unconventional oil and gas resources, and hydraulic fracturing is also used to increase its production. However, the tensile strength of conglomerates with different sizes is various, which has an important impact on the hydraulic fracture propagation in the conglomerate reservoir. To study the tensile strength difference caused by the size of conglomerate gravel, some Brazilian splitting tests were conducted. To find the influence of tensile strength difference on the hydraulic fracture propagation, some true triaxial hydraulic fracturing experiments for layered formations were carried out. The concept of the fracture element in conglomerate formations was proposed. The results showed the following: (i) the tensile strength of conglomerate rock decreased with the increase of the gravel size, and the average tensile strengths of specimens with gravel diameters of 2.0–6.0 mm and 6.0–20.0 mm were 65.5% and 43.6% of that with 0.1–2.0 mm diameter, respectively; (ii) hydraulic fractures easily deflected at the interface of fine-grained conglomerate and medium-grained conglomerate; (iii) hydraulic fractures were prone to propagate to the layers with larger gravel sizes, and the smaller the gravel size, the lower the penetration probability. It is helpful to increase the understanding of the hydraulic fracture propagation under different gravel sizes in the conglomerate reservoir, and it can provide a reference for well distribution and hydraulic fracturing design.

Effect of Hole on Oil Well Cement and Failure Mechanism: Application for Oil and Gas Wells.

Cementing is an important operation in the drilling process. During the cementing process, mud cake, fracturing, perforation, and so on will cause holes in the cement sheath. Thereby, the size effect will reduce the cement strength, which will seriously affect the cementing quality. Several hole types were drilled to study the mechanical properties and damage mechanism of oil well cement. The stress distribution and failure process of cement containing a hole were studied using RFPA2D software. The experimental and simulation results demonstrate that an internal hole has an obvious effect on the cement performance. The hole will change the cement bearing capacity and affect the fracture direction. Three crack types exist: tensile, shear, and far-field. Both 2 and 5 mm vertical eccentric holes can reduce the cement tensile stress. Furthermore, the specimen tensile strength decreases with an increase in the diameter of holes. Horizontal eccentric holes with diameters of 2 and 5 mm will increase the cement tensile strength. Among these, the sample L2-2 exhibits a long crack path, high energy consumption, and a remarkable enhancement effect.

Effectiveness of replacing cement partially with waste brick powder in mortar

This investigation was aimed to find the optimum replacement level of waste brick powder (WBP) as a partial replacement of cement. For this purpose, three groups of tests are made: fresh, mechanical, and permeation properties. Eight mixes with different percentages of replacing ratios are as follows: 10, 15, 20, 25, 30, 35, 40, and 50%. In addition to the reference mix without powder replacements, the experimental programs include three groups of tests: fresh properties (flow test and fresh density), mechanical properties (dry density, compressive strength, and flexural strength), and transport properties (water absorption ratio, rate of water absorption, i.e., sorptivity, and permeable void ratio). Also, an ultrasonic velocity impulse test was made. The flowability and density of fresh mixes are decreased linearly as the amount of WBP increases for the constant water/binder ratio. However, the density of in-hardened state was found to be slightly higher than the reference mix for mixes with a brick powder content up to 20%. Results indicate that strengths for mixes containing WBP are higher than those for the control mix. The highest strength was examined in the mix with 15% WBP for both compressive and tensile strengths of specimens. Generally, the brick powder reduced the ability of mortar to transfer liquid that was clear from the results of permeability test results. Empirical relations were proposed according to experimental results.

Experimental evaluation of multi-functional effects of fibers on mechanical and performance properties of Roller-compacted concrete pavements (RCCP)

The weak performance of asphalt pavements in different climatic conditions, quick decay of pavement, and lack of necessary durability have caused engineers and constructors to try to find Roller Compacted Concrete Pavement (RCCP) for use in various conditions and applications with outstanding properties such as higher durability, and lower maintenance costs. This paper aimed to investigate the mechanical and durability of RCCP by considering different types and amounts of fibers. Cylindrical specimens (with two diameters of 100 and 150 mm) and bending beams with four different fiber types (steel, Kortta Emboss, Kortta Twist, and Sinusoidal plastic) and different percentages were used and subjected to various tests. The compaction time (VB or Vebe) test on fresh concrete, the compressive strength, elastic modulus, the flexural strength, the Brazilian tensile strength, impact resistance, electrical resistance, and skid resistance tests on hardened concrete were conducted. A total of 17 fiber-reinforced concrete mixtures in addition to plain specimen were considered. The test results indicated that compressive, flexural, and tensile strengths of the specimen containing steel fibers were improved up to 27, 83, and 25%, respectively. Moreover, the flexural and tensile strengths of specimens containing Kortta Emboss fibers were improved up to 80 and 19%, respectively. The impact resistance of specimens containing steel and Kortta Emboss fibers were significantly improved up to 270 and 290%. Based on evaluating the results obtained from all tests, Kortta Emboss fiber was proposed as the best option among the studied fibers to improve the properties and functions of RCCP.

Pengaruh Media Pendingin pada Perlakuan Panas T6 terhadap Kekuatan Tarik dan Struktur Mikro Komposit Al6061-Pasir pantai

Al6061-sea sand composite was manufactured using the stir casting method and its mechanical properties were improved by heat treatment. The T6 heat treatment used to improve the mechanical properties of the composite consists of the following processes: solution heat treatment, quenching, and artificial aging. The solution heat treatment process was carried out at a temperature of 540 o C for 6 hours. The quenching process was carried out with different quenching agents (water, oil, and 10% brine). The difference in quenching agents resulted in different cooling rates. After quenching, an artificial aging process was carried out at a temperature of 200 o C for 4 hours. The difference in cooling rate affects the hardness and tensile strength of the specimen. The high cooling rate results in an increase in the tensile strength of the specimen. This is due to the increase in cooling speed, the Mg 2 Si precipitates formed are smaller in size and located in the grains. The highest tensile strength of specimen (206.67 MPa) is obtained by using brine quenching agent.

Application of non-contact strain measurement based on CCD camera in PMMA material constitutive model

The Jiangmen Underground Neutrino Observation (JUNO) will build a polymethyl methacrylate (PMMA) spherical vessel of a diameter of 35.4 meters. The constitutive model of PMMA is a key parameter for the design of PMMA structure. The bulk polymerization bonding area is often the weak point of the PMMA structure, so it is useful to understand the constitutive model of bonding areas for FEA. However, the traditional contact strain measurement methods, such as the strain extensometer and resistance strain gauge, will have an impact on the strain of PMMA, as the lossy measurement. Traditional measuring methods also can’t measure the small-sized bonding areas as 3 mm in most structures. The non-contact strain measurement method based on the CCD camera is studied. The tensile test result shows that the influence of environment on the strain value is less than 0.01%. The two strain measurement methods, the CCD camera and strain extensometer, are compared. The strain curves obtained by the two methods are highly consistent, and the maximum strain difference is 8.53 e-4. The fracture strain of the PMMA tensile specimen is 4.32% and slight plastic deformation has occurred. The Zhu-Wang-Tang (ZWT) nonlinear viscoelastic constitutive model of PMMA is obtained by fitting the stress-strain data. The tensile test result of PMMA specimen with bulk polymerization bonding area shows that the constitutive equations are different when the length ratio of the bonding area is different. By analyzing the relationship between the length ratio and the coefficients of constitutive equation, the constitutive equation of the bonding area is finally obtained. The results show that the coefficient of the constitutive equation of the bonding area is smaller than that of the mother material. The fracture strain of PMMA specimen with bonding area is 2.60%, lower than that of mother material, which makes the coefficient of the bonding area constitutive equation opposite to the sign of the mother material. The tensile strength of specimen with bonding area is about 85.68% of that of the mother material. The lower tensile strength makes the bonding area become one of the weak points of the structure.