Structural testing testing steel truss under static load experiment purpose and requirement for testing steel truss

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY OFFICE FOR INTERNATIONAL STUDY PROGRAMS STRUCTURAL TESTING Student : Do Tan Kiet ID number : 1852490 Adviser : Assoc Prof Ho Duc Duy Subject code : CI4011 Ho Chi Minh City, November 2022 PREFACE Structural inspection course has played a big role for most students majoring in civil engineering including those who have graduated from university and take it as a guide The course sets out essential design theory and illustrates practical applications in our profession Topics have broadened our horizons of some of the widely used experiments in civil engineering, but they have also given us broad access to learning and self-improvement Especially, after participating in the structural experiment course, we have learned and made great progress in the necessary knowledge such as (i) equipment and measuring instruments used in experimental survey, (ii) testing to determine the mechanical characteristics of concrete and steel, (iii) evaluating the performance of the structure by loading test and (iv) verifying the quality of the work Overall, I would like to express my great appreciation to Assoc GS Ho Duc Duy about the valuable knowledge and valuable advice that he has taught and shared during this course Signature Contents EXPERIMENT 1: TESTING STEEL TRUSS UNDER STATIC LOAD 1.1 Experiment purpose and requirement for testing steel truss: 1.1.1 Experiment: 1.1.2 Requirement for testing steel truss: 1.2 Experimental diagram: 1.3 Apparatus: .7 1.3.1 Hydraulic pump: 1.3.2 Strain measurement equipment: .8 1.3.3 Dial indicator: 10 1.3.4 Load cell: .11 1.4 Procedure: 11 1.4.1 Preparation: 11 1.4.2 Testing procedure: .11 1.5 Testing result: 12 1.6 Calculated data: 12 1.7 Theoretical calculation of stress, strain, deflection: .13 1.7.1 1.8 Modeling the steel truss using SAP2000: 13 Result and discussing: 17 1.8.1 Comparison between testing method and SAP modelling method: 17 1.8.2 Discuss the result between testing and SAP modelling method: 23 1.8.2.1 : Comment on chart result: 23 1.8.2.2 Cause of differences: .23 EXPERIMENT 2: REINFORCED CONCRETE BEAM 25 2.1 Experimental purpose: .25 2.2 Experimental diagram: 25 2.3 Apparatus: 26 2.4 Procedure: 27 2.4.1 Preparation: 27 2.4.2 Testing procedure: .28 2.5 Testing result: 28 2.6 Calculated data: 29 2.6 Theoretical calculation of stress, strain, deflection: 30 2.6.1 Reinforcement concrete theory: 30 2.6.1.1: Initial data: .30 2.6.1.2: Deflection: 31 STRUCTURAL TESTING SUBJECT QUESTION .36 LIST OF FIGURES Figure Steel truss diagram Figure Steel truss experiment under static load Figure Hydraulic pump Figure Switch and Balance Unit SB10 Figure Vishey measurement P3500 Figure Strain gage 10 Figure Dial indicator 10 Figure Steel truss 10 Figure Load cell .11 Figure 10 Axial force of the steel truss for case F 1=1.5kN 16 Figure 11 Deflection node I 18 Figure 12 Deflection Node II 19 Figure 13 Strain gage 20 Figure 14 Strain gage .21 Figure 15 Strain gage .21 Figure 16 Strain gage .21 Figure 17 Strain gage .22 Figure 18 Strain gage .22 Figure 19 Strain gage .22 Figure 20 Concrete beam diagram .25 Figure 21 Reinforced concrete beam testing at the laboratory .26 Figure 22 Hydraulic jack and load watch for applying and controlling load .27 Figure 23 Switch and Balance Unit SB0 and P3500 27 Figure 24 General dimension for all 30 Figure 25 Loading action on beam according to the first level of load (i=1) 32 Figure 26 Moment distribution of beam according to the first level of load (i = 1) 32 Figure 27 Case of loading RC beam 34 LIST OF TABLES Table Result of deflection and strain for the 1st experimental testing 12 Table Result of deflection and strain for the 2nd experimental testing .12 Table Calculated result of deflection and strain for the 1st experimental testing 13 Table Calculated result of deflection and strain for the 2nd experimental testing 13 Table Average the calculated result of deflection and strain for the experimental testing 13 Table Summarize the result of deflection and axial force from ETABS 17 Table Summarize the result of deflection and strain value according to elastic theory .17 Table Comparison the deflection result between testing method and SAP2000 .18 Table Comparison the strain result between testing method and SAP 19 Table 10 Result of deflection and strain for the 1st experimental testing 29 Table 11 Result of deflection and strain for the 2nd experimental testing 29 Table 12 Calculated result of deflection and strain for the 1st experimental testing 29 Table 13 Calculated result of deflection and strain for the 2nd experimental testing 30 Table 14 Average the calculated result of deflection and strain for the experimental testing 30 Table 15 Summaries the calculation of stiffness factor  33 EXPERIMENT 1: TESTING STEEL TRUSS UNDER STATIC LOAD 1.1 Experiment purpose and requirement for testing steel truss: 1.1.1 Experiment: Become familiar with the method of testing a bar structure, know how to use measuring devices to determine experimentally stress and displacement Determine the stress in the truss rod, deflection, displacement of the truss From there, compare the results between theory and experiment when considering: • Stress (expressed through strain) of truss rod • Deflection and displacement at some positions on the steel truss 1.1.2 Requirement for testing steel truss: • Measure strain  at some representative bars in the array Stress  and internal force N in truss bars • Measure deflection  at some positions on the truss • Compare experimental and theoretical results 1.2 Experimental diagram: Figure Steel truss diagram     The steel truss has trapezoid shape, including spans, each span has 0.5m in height and 1m in length Structure of truss steel bars as in the following table: Piston diameter: 5.6 cm Gusset plate thickness: 4-5mm Chord and side web Specifications Area(A) (cm2) X-axial moment of inertia Jx (cm4) Modulus E (N/cm2) 2L40x40x5 7.58 5.4 2.1x107 Interior web 2L40x40x4 4.54 1.8 2.1x107 1.3 Apparatus: 3 Figure Steel truss experiment under static load with Hydraulic pump Strain measurement equipment Dial indicator Strain gage 1.3.1 Hydraulic pump: Scope:  To create stress (daN/cm2) through the load cell acting on the fully rigid beam, then transfer the reaction force to the sides of the steel truss as showed in the above figure  The load acting on the sides of the truss is calculated as follow: ( F= v × where: ) πd ÷2 v: Pressure value that read on gauge (daN/cm2) d: Diameter of the piston (mm) Figure Hydraulic pump   The testing uses the 20 tons’ hydraulic pump with the piston diameter (d = 56mm) The process of loading and unloading of the hydraulic pump equipment should be processed by each loading level After unloading the pressure to zero, wait about 10 minutes to continue to operate 1.3.2 Strain measurement equipment: Figure Switch and Balance Unit SB10  • Figure Vishey measurement P3500  Switch and Balance Unit SB10: Including 10 channels plus open position that allow to measure up to 10 strain gages at the same time The equipment consists a switch button to determine each value of strain gages The channel switch of the SB-10 has an open position to allow the use of additional SB-10’s with a single P-3500 strain indicator The combination of a P-3500 and SB-10 allows the operator to intermix, in a single 10- channel system, quarter, half and full bridge circuits Vishay measurement P3500: • The model P-3500 Vishay measurement is a portable, battery- • powered instrument with unique features for use in stress analysis testing and for use with strain gauge-based transducer • The value extracted from the electronic meter of the device showed the negative value is for the strain gage location that are under compression, and positive value for tensioning  Strain gage:  Based on tensest effect, when the conductor is mechanically deformed, the resistance also changes The value extracted from the Vishay measurement based on the following formula: ε g= ∆ R g / Rg GF Figure Strain gage 1.3.3 Dial indicator: Small displacement gauges:   The type of gauge used in the experiment is an electronic clock That scale is mm Minimum division 0.01mm In the experiment, install clocks to measure the deflection of button positions in the steel frame Corresponding to the increasing or decreasing displacement of each node position that we set the clock up or down Figure Dial indicator 10 + For dial micrometer: Dial micrometer II is located in the middle of the beam, which is placed below the concrete beam Figure 21 Reinforced concrete beam testing at the laboratory where: 1: P3500 and SB10 equipment 2: Load cell 3: Hydraulic jack 4: Machine that show the force value 2.3 Apparatus: The equipment of reinforced concrete beam testing is similar to the first experiment (steel truss testing), therefore, we will not mention again the function of each equipment in this part 26 Figure 22 Hydraulic jack and load watch for applying and controlling load Figure 23 Switch and Balance Unit SB0 and P3500 2.4 Procedure: 2.4.1 Preparation: Some members will be assigned some tasks, their tasks are as follows: - Phuc Dat: Adjusting the hydraulic pump into the specific pressure level that the instructor has already required - Lai Khang: Recording the result and summarize all of the information for the group to assembled into the report - Minh Duy: Set up and checking the result extracted from the P3500 - Huynh Duyen: Set up and checking the dial micrometer value 27 - Others on the team were responsible for assisting with the lighting, taking pictures of the equipment, and checking the metrics 2.4.2         Testing procedure: Checking all of the equipment that are all in normal condition Setting up the machine, reset the dial indicator to value Take note the initial value (deflection and strain) from the dial indicator and Vishey measurement at stress daN/cm2 as the standard value Increased stress gradually, from to 4-8-12-16 (kN) from above the concrete beam When it reach to the required stress level, recording the value of deflection from the dial indicators and strain value of strain gage from Vishey measurement When the stress reached the maximum required value (12kN), unloading the hydraulic pump to zero, and wait for 10 minutes and continue the above procedure to measure the second time Note: The deflection value from the dial micrometer is rounded to decimal places The positive value (+) of strain corresponding to tension, and the negative value (-) of strain is for compression 2.5 Testing result: After testing for times, the results from experiment will be summarize in these following table Table 10 Result of deflection and strain for the 1st experimental testing Force F (kN) Deflection value from dial indicators (mm) I 4.00 8.00 12.00 II 0.000 0.277 0.584 0.862 Strain value from P3500 (με) III -0.327 -0.352 -0.374 -0.389 28 -0.293 -0.258 -0.221 -0.183 -0.123 -0.093 -0.052 -0.014 16.00 1.146 -0.410 -0.140 -0.027 Table 11 Result of deflection and strain for the 2nd experimental testing Force F (kN) Deflection value from dial indicators (mm) I II 0.008 0.286 0.584 0.870 1.147 4.00 8.00 12.00 16.00 Strain value from P3500 (με) III -0.331 -0.354 -0.371 -0.391 -0.411 -0.283 -0.247 -0.211 -0.172 -0.139 -0.120 -0.087 -0.049 -0.011 -0.029 2.6 Calculated data: The testing result are assumed that the initial displacement and strain values still existed since this is the old steel truss and has been used for various of experiments Therefore, these values should be converted by subtracting the original value to consider the initial displacement and strain to be - Assumed that the results at the initial stage i = Table 12 Calculated result of deflection and strain for the 1st experimental testing i Force F Force F/2 (kN) (kN) Deflection value from dial Strain value from P3500 indicator (mm) (με) △L = Li – Li=1 ε = ε i –ε i=1 I II III 0 0 0 0.277 -25 35 30 0.584 -47 72 71 12 0.862 -62 110 109 16 1.146 -83 153 96 Table 13 Calculated result of deflection and strain for the 2nd experimental testing i Force F (kN) Force F/2 (kN) Deflection value from dial Strain value from Vishay indicator (mm) measurement (με) △L = Li – Li=1 I 0 II 29 ε = ε i –ε i=1 III 0 0.278 -23 37 33 0.576 -40 73 71 12 0.862 -60 112 109 16 1.139 -80 145 91 Table 14 Average the calculated result of deflection and strain for the experimental testing i Force F Force F/2 (kN) (kN) Deflection value from dial Strain value from Vishay indicator (mm) measurement (με) △ Lave = I (∆ L1st + ∆ Lnd2 ) st nd ε +ε ) ( ε= II III 2 0 0 0 0.2775 -24 36 31.5 0.58 -43.5 72.5 71 12 0.862 -61 111 109 16 1.1425 -81.5 149 93.5 2.6 Theoretical calculation of stress, strain, deflection: 2.6.1 Reinforcement concrete theory: 2.6.1.1: Initial data: Material: Concrete C25/30 , fck = 25MPa; fctm = 2.6MPa; Ecm = 31 GPa Longitudinal rebar fyk = 400MPa; Es = 21×104 MPa Stirrup bar fyk = 240MPa Section properties: As = 603 mm2 (3d16); As2 = 157 mm2 (2d10); b = 150mm; h = 300 mm; d2 = 35 mm (a = 35mm); d = 35 mm Figure 24 General dimension for all So, Beam cracked at mid-span section before testing 2.6.1.2: Deflection: • Step 1: Find the effective modular ratio αe Ec , eff = Ecm 31000 = = 8378,3784 MPa (⏀=2.7 is the creep coefficient) 1+⏀ 1+2.7 30 αe = ã Es 21 ì10 = = 25.0645 Ec ,eff 8378,3784 Step 2: Calculate the cracking moment  For un-cracked case Let x = xu b×h + α e x A s × d+ α e × As ×d x x= u= b × h+α e × A s +α e × A s 150 x 3002 +25.0645 x 603 x 265+25.0645 x 157 x 35 = = 170 mm 150 x 300+25.0645 x 603+25.0645 x 157 So S1 = As×(d – x) = 603×(265 – 170) = 57285 mm2 I = b ×h +b×h×( h −x) + α e × A s ×(d−x)2 + α e × A s ×( d−x)2 12 = 150 x 3003 300 −170) + 25.0645 ×603 ×(265−170)2 + + 150 × 300 × ( 12 2 25.0645 x 157 ×(35−170) = 563620570 mm4 σ t = f ctm => M cr = f ctm x I 2.6 x 5636205 70 = = 11.2726 kNm 300 – 170 h−xu With the moment Mcr = 11.2726 kNm, it will cause crack for the beam, applying the knowledge of strength of material to determine the additional load Fcr acting on the structure to cause the moment Mcr = 11.2726 kNm M cr = F cr x L → F cr = M cr 11.2726 = = 12.528 kNm 0.9 L The value Fcr is the additional force to cause the cracking moment 31 Then we will combine with the initial force from the experiment, the result for each concentrated load acting on the RC beam is: F t ,i =Fcr +Fi Fi =12.528 + 2 Where Fi is the initial force from the experiment corresponding to each level of load i The distribution coefficient is: ξ=1–βx( M cr 12.528 ) = – 0.5 x ( M ) Mi i Where Mi is the moment at mid-span caused by load F(t,I) corresponding to each level of load i The result Mi is extracted by using SAP2000 12.528 12.528 Figure 25 Loading action on beam according to the first level of load (i=1) 11.2725 11.2725 11.2725 Figure 26 Moment distribution of beam according to the first level of load (i = 1) Similar to other level of load, the result for all calculation will be summaries in the following table: 32 Table 15 Summaries the calculation of stiffness factor  Mi (kNm) Stiffness factor F/2 Fi (kN) 12.528 2 14.528 13.0725 0.453 16.528 14.8725 0.42 18.528 16.5725 0.431 20.528 18.4725 0.444 No I II 11.2725 III I II 0.444 For crack case: xc = x [(αe × AS + αe×AS2) + b √(α e × A S+ α e × A S 2) + 2× b × ( α × d × A + α × d × A ) ] √(α e × A S+ α e × A S 2) + x b x ( α × d × A + α × d × A e s e e s2 s e s2 ) √ ( 25.0645 x 603+25.0645 x 157 ) +2 x 150 x ( 25.0645 x 265 x 603+25.0645 x 35 x 157 ) = 40071.6674 mm2 → xc = - Αe x ¿ + A s 2) = -25.0645 x ¿ +157) = -19049.02 mm2 ; - 1 = mm b 150 x (-19049.02 + 40071.66735) = 140 mm 150 b x x 3c I2 = + αe ׿ + A s ×( x−d 2)2 ] 12 150 x 140 = + 25.0645 x ¿ + 157 x (140−35)2 ] = 313839356 mm 12 The flexural curvature 1/r m = ξ x ψ + (1 – ξ) x ψ rm 33  III Step 3: Calculate the flexural curvature 1/rm = ξ x ψ + (1 – ξ) x ψ rm Where ξ is the distribution coefficient that already calculated in the table 15 ψ 1is the curvature of un-cracked section ψ = ψ 2is the curvature of cracked section ψ = Mi Mi = Ec ,eff x I 8378,3784 x 5636205 70 Mi Mi = Ec ,eff x I 8378,3784 x 313839356 M is the moment value, caused by force F/2 In general, the formula for the flexural curvature for each level of load i is: ( ) 〖 Mi Mi ξ i) × 〗 = ξi x + (1 – rm 8378,3784 x 313839356 8378,3784 x 56362056 70 i Calculate the deflection δ δ i = K x L2 × ( ¿ Rm i Where: + K: can be determine based on each case of loading Figure 27 Case of loading RC beam ( ) = 0.1065 a K = 0.125 – = 0.125 - 6 + L: length of RC beam (L = 2.7m) + 1/rm is the flexural curvature The result for step and will be summaries in the following table: 34 F i F/2 (kN) Flexual curvature 1/r m M i (kNm) Force I II III (1/mm) I II III Deflection δ (mm) I II 0 2 1.8 5.39 x 10-7 0.42 3.6 1.11 x 10 -6 0.86 5.4 1.71 x 10-6 1.33 7.2 2.33 x 10-6 1.81 2.6.1.3 Strain: 35 III STRUCTURAL TESTING SUBJECT QUESTION Question 0: Opinions about structural testing subject: Structural testing is a specialized subject in the training program of civil engineering This is an essential subject that helps students have a more realistic view of the field and provides knowledge that is directly related to other specialized subjects, such as reinforced concrete structures, structural engineering steel, building foundations and as well as construction techniques A very important part of the curriculum is that students must know how to calculate based on theory to put into practice laboratory experiments In addition, after graduation, the knowledge of the subject of engineering experiments also plays an important role for students in their work, because in reality every project requires experiments and we have to compare them Compare the calculation results to ensure absolute accuracy In addition, this subject provides students with the task of experimental research including assessing the performance, longevity of the structure and new methods of application because it greatly affects the life People This is why it is so important when doing construction tests Question 1: Methods for Testing Compressive Strength of Concrete Rebound Hammer or Schmidt Hammer (ASTM C805) Method: A spring release mechanism is used to activate a hammer which impacts a plunger to drive into the surface of the concrete The rebound distance from the hammer to the surface of the concrete is given a value from 10 to 100 This measurement is then correlated to the concretes’ strength Pros: Relatively easy to use and can be done directly onsite Cons: Pre-calibration using cored samples is required for accurate measurements Test results can be skewed by surface conditions and the presence of large aggregates or rebar below the testing location Penetration Resistance Test (ASTM C803) Method: To complete a penetration resistance test, a device drives a small pin or probe into the surface of the concrete The force used to penetrate the surface, and the depth of the hole, is correlated to the strength of the in-place concrete Pros: Relatively easy to use and can be done directly onsite Cons: Data is significantly affected by surface conditions as well as the type of form and aggregates used Requires pre-calibration using multiple concrete samples for accurate strength measurements Ultrasonic Pulse Velocity (ASTM C597) Method: This technique determines the velocity of a pulse of vibrational energy 36 through a slab The ease at which this energy makes its’ way through the slab provides measurements regarding the concrete’s elasticity, resistance to deformation or stress, and density This data is then correlated to the slab’s strength Pros: This is a non-destructive testing technique which can also be used to detect flaws within the concrete, such as cracks and honeycombing Cons: This technique is highly influenced by the presence of reinforcements, aggregates, and moisture in the concrete element It also requires calibration with multiple samples for accurate testing Pullout Test (ASTM C900) Method: The main principal behind this test is to pull the concrete using a metal rod that is cast-in-place or post-installed in the concrete The pulled conical shape, in combination with the force required to pull the concrete, is correlated to compressive strength Pros: Easy to use and can be performed on both new and old constructions Cons: This test involves crushing or damaging the concrete A large number of test samples are needed at different locations of the slab for accurate results Drilled Core (ASTM C42) Method: A core drill is used to extract hardened concrete from the slab These samples are then compressed in a machine to monitor the strength of the in-situ concrete Pros: These samples are considered more accurate than field-cured specimens because the concrete that is tested for strength has been subjected to the actual thermal history and curing conditions of the in-place slab Cons: This is a destructive technique that requires damaging the structural integrity of the slab The locations of the cores need to be repaired afterwards A lab must be used to obtain strength data Cast-in-place Cylinders (ASTM C873) Method: Cylinder molds are placed in the location of the pour Fresh concrete is poured into these molds which remain in the slab Once hardened, these specimens are removed and compressed for strength Pros: Is considered more accurate than field-cured specimens because the concrete is subjected to the same curing conditions of the in-place slab, unlike field-cured specimens Cons: This is a destructive technique that requires damaging the structural integrity of the slab The locations of the holes need to be repaired afterwards A lab must be used to obtain strength data Wireless Maturity Sensors (ASTM C1074) Method: This technique is based on the principle that concrete strength is directly related to its hydration temperature history Wireless sensors are placed within the 37 concrete formwork, secured on the rebar, before pouring Temperature data is collected by the sensor and uploaded to any smart device within an app using a wireless connection This information is used to calculate the compressive strength of the in-situ concrete element based on the maturity equation that is set up in the app Pros: Compressive strength data is given in real-time and updated every 15 minutes As a result, the data is considered more accurate and reliable as the sensors are embedded directly in the formwork, meaning they are subject to the same curing conditions as the in-situ concrete element This also means no time is wasted onsite waiting for results from a third-party lab Cons: Requires a one-time calibration for each concrete mix to establish a maturity curve using cylinder break tests Question 3: In order to determine the strength of concrete on the structure, the following requirements must be met: – The procedures for the use of non-destructive methods in the respective test standards shall be followed; – It is necessary to build a standard curve showing the relationship between the parameters determined by non-destructive methods and the concrete strength determined on the drilled samples that can be obtained, or stored concrete samples of the work or concrete samples concrete with the same fabrication conditions as structural concrete as directed in the respective test standards The compressive strength of concrete is determined on the basis of comparing this measured bounce value with the measured bounce value in the built-in test standard on the relationship between the compressive strength of the samples concrete on the compressor (R) and the average bounce value on this trigger gun are obtained from the test results on the same test specimen To grind, use the R - n standard, sur- ing the blood pressure 150x150x150 mm according to the requirements of TCVN 3105: 1993 When the test is done to determine the value of this comparison in the horizontal direction, the size is small on a compressor with a pressure of daN/cm? When testing the determination of this ratio according to the above-mentioned standards, the blood and concrete The weight is above the weight, so the weight of the wife is not more than 500 kg For position and comparison of scores on the sample, see 4.7 and 4.12 When checking for a child's scratch for a type, the relationship is RIGHT n duo use according to the test results of at least 20 samples (each team collected samples) Codes must have the same level of strength, age, and performance 38 Use this method to clean up the mess, safe to check You're going to have to lay your hands on them are different for a period of no more than weeks If the relationship between R - n is more variable, it can be rated at 40% The test sample had a difference in the ratio of water-cement (N/X) within the period of +0.04 compared with the ratio of water-cement (N/X) of the test worm 39 REFERENCES [1] Nguyen Thanh Ngoc Structural testing report HCMC University of technology – faculty of Civil Engineering [2] Tran Thai Minh Chanh 2014 Báo cáo Thí nghiệm Công trình, HCMC Available from: Thuviendientu (accessed 5/11/2021) [3] Ho Duc Duy 2021 Structural testing lecture HCMC University of technology – faculty of Civil Engineering [4] Ngo Huu Cuong 2020 Steel structural lecture HCMC University of technology – faculty of Civil Engineering [5] Tavio et al 2018 Tensile strength/yield strength (TS/YS) ratios of high-strength steel (HSS) reinforcing bars 020036 AIP Conference Proceedings [6] Saif Aldabagh, M Shahria Alam 2020 High-Strength Steel Reinforcement (ASTMvA1035/A1035M Grade 690): State-of-the-Art Review Journal of Structural Engineering: ASCE [7] Bhushan Mahajan 2021 Ultrasonic Pulse Velocity Test: Civiconcepts [8] Ho Huu Chinh 2020 Reinforced of concrete structure HCMC University of technology – faculty of Civil Engineering [9] Tiêu chuẩn xây dựng Việt Nam TCXDVN 162:2004 Bê tông nặng 40 ... 33 EXPERIMENT 1: TESTING STEEL TRUSS UNDER STATIC LOAD 1.1 Experiment purpose and requirement for testing steel truss: 1.1.1 Experiment: Become familiar with the method of testing a bar... knowledge and valuable advice that he has taught and shared during this course Signature Contents EXPERIMENT 1: TESTING STEEL TRUSS UNDER STATIC LOAD 1.1 Experiment purpose and requirement for testing. .. Deflection: 31 STRUCTURAL TESTING SUBJECT QUESTION .36 LIST OF FIGURES Figure Steel truss diagram Figure Steel truss experiment under static load Figure