35 results about "Equivalent static load" patented technology

The invention relates to a dynamic response topological optimization method implemented by application of improved bi-directional evolutionary structural optimization (BESO) to an equivalent static load method. In the method, improved BESO is applied to the equivalent static load method to form an optimized iteration method for replacing an original variable density method, and establish a new convergence condition in order to improve a dynamic response topological optimization flow. By adopting the method, optimization time of a design circulation stage of which k is greater than 1 can be reduced effectively, and CPU (Central Processing Unit) total time needed by optimization in two examples is reduced by 21.8 percent and 25.3 percent compared with an original method; the method has the characteristics of high computation speed and simple optimization flow; along with the increase of external load acting points and the expansion of the optimization scale, design circulation times needed by optimization are increased, and the method has greater advantages.

The invention discloses a method for quantitatively analyzing the starting capability of a stepping motor, comprising: (1) testing the maximum static starting torque of the stepping motor at different starting frequencies, and drawing the static torque-frequency characteristic curve of the motor; (2) The stepper motor rotor is affected by the initial speed and initial position when it is dynamically started, which is equivalent to the initial speed equivalent load torque T L1 and initial position equivalent load torque T L2 ; (3) According to the actual initial running state of the stepper motor and the actual load torque T L , and further obtain the total equivalent static load at each initial speed and initial position when dynamic starting; (4) compare the total equivalent static load with the maximum static starting torque at a specific starting frequency, and judge that the stepper motor is at Whether it can start normally at this starting frequency. With the invention, the initial speed and the initial position can be equivalent to the equivalent load torque, so that the dynamic starting performance of the stepping motor can be analyzed by using the static torque-frequency characteristic.

The invention belongs to the structure and equipment impact resistance design technology field and relates to a method of determining an impact-load equivalent static load. The method comprises the following steps of step1, according to the following formula which is defined in the description, calculating a dynamic scaling coefficient lambda, wherein TD is duration of an impact load, and fn is a fundamental frequency of a structure to be impacted; and step2, according to the following formula, calculating an equivalent static load Ps of the impact load, wherein the formula is Ps=lambda P, and the P is a peak value of the impact load. A lambda value acquired through calculation in the scheme can be greater than and less than 1 according to a change of TDfn, which is really equivalent to the impact load, and a truth degree of the equivalent static load is increased.

The invention belongs to the technical field of automobiles, in particular to a method for optimizing the size of an automobile bumper mask based on an equivalent static load method. The invention takes the total mass of the automobile bumper mask as the objective function, the displacement as the constraint, and the thickness of the mask as the design variable to optimize the size of the bumper mask. The present invention requires that the final optimization result not only meets the convergence condition, but also needs to satisfy the displacement constraint condition, and the optimization result is more accurate. In addition, the present invention only calculates the equivalent static load of the time step where the displacement is the largest, and does not need to calculate the equivalent static load of all time steps, and the calculation efficiency is high. The invention uses matlab to integrate all the above functions to realize automatic solution. Except for basic model preprocessing, it is not necessary to open finite element software to solve the model, and the running program directly calls the relevant solver to solve, and the operation is convenient.

The invention discloses a method for designing a hybrid fiber composite anti-explosion tank. The hybrid fiber composite anti-explosion container tank is obtained with an anti-explosion tank mechanical property determining method and a fiber hybrid ratio determining method based on anti-impact performance. The method is characterized by including the steps that impact loads of the anti-explosion tank during an explosion are obtained through the incoming overpressure, the reflecting overpressure and the power coefficient generated during a TNT explosion with an equivalent static load method; the stress borne by fibers is calculated through a grid theory in cooperation with a direct cylinder section and an end socket section of the anti-explosion tank, and the thickness of the wound fibers is obtained; the anti-impact performance in the fiber level is evaluated by introducing fiber energy absorption, and an anti-impact performance judgment criterion in the equivalent anti-explosion structure level is obtained; and the fiber ratio generated when the anti-impact performance is highest is selected as the optimal hybrid ratio by controlling the mass and the elastic modulus of the anti-explosion tank. According to the method, due to the anti-impact performance judgment criterion and the hybrid fiber anti-explosion tank optimal hybrid ratio determining method, powerful bases are provided for designing and manufacturing of the hybrid fiber composite anti-explosion tank.

The invention discloses a method for carrying out structural topological optimization on nonlinear dynamic systems of high-speed light-load mechanisms. According to the method, the number of linear static structure optimization iterations in an ESLM (equivalent static loads method) is restricted according to the minimum number of iterations required by the structural topological optimization, so that the modifier in the optimization is restricted, the model error caused by equivalent load is reduced, and the structural topological optimization of the high-speed light-load mechanisms on the basis of structure restricted modified ESLM. According to the method, the equivalent load is considered as a function of a design variable, the optimization model is reconstructed, and a corresponding solving method is proposed, so that the residual amplitude is reduced as much as possible while the optimization condition is satisfied, compared with the standard equivalent static load, the amplitude under the same movement condition can be reduced by a half, the performance of the high-speed light-load mechanisms can be greatly improved and different design requirements of the high-speed light-load mechanisms can be satisfied.

The invention discloses a topological parameter hybrid optimization method for a nonlinear dynamic system structure of a high-speed light load mechanism. According to the method, a linear structure optimization iteration of a standard ESLM (equivalent static loads method) is defined into a single modification, so that a change of an inertial load caused by a structure modification is immediately reflected into an optimization model; a structure with the minimal equivalent load change is obtained; and aiming at a problem that a topological structure tending to 0 or 1 cannot be obtained by the single modification, the standard ESLM is further introduced to obtain a clear topological optimization structure, so that the hybrid optimization of the high-speed light load mechanism on the basis of a single or maximum iteration ESLM is achieved. According to the topological parameter hybrid optimization method, equivalent loads are considered into a function of a design variable; the optimization model is reconstructed; a corresponding determining method is provided; the residual amplitude can be lowered to the maximal extent under the condition of meeting optimization conditions; compared with standard equivalent static loads, the amplitude under the same motion condition can be lowered by a half; the properties of the high-speed light load mechanism are greatly improved; and different design requirements of the high-speed light load mechanism are met.