Ls-dyna crack 971. Chapter 8

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ls-dyna crack 971

Figure 96 presents the force-deflection relationships obtained from both simulation and testing of both the rigid pole and T4 bridge rail with 317. The original mesh of the parapet was constructed to enforce matching between nodes of concrete and those of the steel reinforcement. The data for test P3 deviates from test P4 and the simulation before rebound. Boundary conditions used for the full system model with deck and for the parapet-only model. Full System Analysis: Three-Bolt Design The same parameters used in the simulation of the T4 bridge rail with four-bolt anchorage and 254-mm- 10-inch- wide parapet were incorporated into the full system model of the T4 bridge rail with three-bolt anchorage and 317. As shown in Figure 116, the associated fracture profile radiated out from the outer anchor bolts on the top of the parapet but did not extend to the field side of the parapet. Due to the inherent flexibility of the bridge deck, the fracture profile of the concrete parapet was less severe than that for the parapet-only model and was similar to that observed in the pendulum tests.


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Chapter 8

ls-dyna crack 971

As damage of the concrete components increases as indicated by the damage fringes and contours , the total system energy increases. Contacts definitions for the T4 bridge rail model. For the bridge deck, which had an average compressive strength of 35. Note that the pendulum follows a circular arc. The impact loads were transferred to the concrete parapet and deck through the steel rail. Parapet damage after test P5, rear. Bug fix for output crack data to crack file.

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ls-dyna crack 971

Second, the concrete material model was used in the impact analysis of a roadside safety structure in which some concrete failure was observed. Beyond test variability, the cause of the difference in peak force is not known. This contact definition was not used when the parapet-only model was being analyzed. Realizing that fracture energies set at 27. Because these data are based on integration of the acceleration data, they are expected to be smoother and correlate better.

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Chapter 8

ls-dyna crack 971

Next, further study was devoted to the connection between the base plate and anchor bolts. Figure 126 presents the velocity-time histories for the pendulum tests and simulation. Long input format for parapet concrete material model. Comparison of data from the rigid pole calibration tests and the T4 bridge rail impacts showed a discrepancy in the stiffness of the nose assembly. It was analytically verified through careful monitoring of bolt stresses that none of the anchor bolts reached yield stress at any time during simulation. The pre-processor used for this study was HyperMesh ®. The nose of the pendulum bogie contacted the elliptical tube on the steel rail portion of the system.

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ls-dyna crack 971

Model of T4 bridge rail specimen with four-bolt anchorage and 254-mm- 10-inch- wide parapet. G fc Fracture energy in uniaxial compression. The anchor bolts were modeled using elastic steel definition due to their size 19. Additional checks on the properties of the aluminum honeycomb material commonly used in the crushable nose assembly of the pendulum bogie indicated that the material stiffness can vary considerably e. Parapet damage after test P5, side.

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ls-dyna crack 971

Force-time histories for benchmark tests and spring models. The contact definition between the parapet and deck represents the construction joint that exists between these two components. However, when these values were obtained, it was noticed that the printed output did not correspond to the format provided in the draft manual. Together, the concrete parapet and deck models had a total of 115,000 elements. The enhanced connection model between the base plate and anchor bolts is depicted in Figure 119.

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ls-dyna crack 971

More specifically, the total energy of the system increased. Ls Dyna Student Version Memory reqd for. After calibration of the material model parameters and enhancement of the base plate connection model, simulations of the two bridge rail alternatives were able to capture the general pattern and severity of concrete damage observed in pendulum tests of both the 254-mm- 10-inch- and 317. The other variables were unchanged from their baseline values. As shown in Table 12, the peak impact force in the simulation of the T4 bridge rail system with four-bolt anchorage compares favorably with those measured in the corresponding pendulum tests.

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ls-dyna crack 971

Is there any way I can get the cracked version of ls-dyna. In the second variation, the width of the concrete parapet is 317. Figure 127 shows the calculated response of the parapet-deck system after being impacted by the pendulum. Thus, the linear motion prescribed is an approximation, which is accurate within a small displacement setting as is the case with the T4 bridge rail. These tests were conducted on the same day on two different test specimens under nominally similar impact conditions. The concrete used for the bridge deck had an average compressive strength of 35.

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Chapter 8

ls-dyna crack 971

Analyses of T4 bridge Rail Numerous analyses were conducted using the models of the T4 bridge rail variants as part of the evaluation of the concrete material model. Bell curve mesh biasing along length of parapet and uniform meshing along length of deck. The tubular rail, the base plate, and the steel posts were modeled using an elastoplastic material model definition. A constraint was used to represent the interaction between the anchor bolts, steel reinforcement, and the surrounding concrete continuum. The research team used the Linux Intel 32 bit architecture version 971 release 1708 single precision release to maintain consistency and avoid potential software glitches associated with beta releases that occurred subsequent to the project's initiation. However, unlike the tests, no material failure i. Short input format for bridge deck concrete material model.

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