Static Shape and Stress Control of Trusses with Optimum Time, Actuators and Actuation

Abstract

Traditional shape and stress control of structures use many actuators and require enormous time to find reasonable solutions that need designers to input specific target displacement and stress. This study employs a linear technique to static shape and stress control of pin-jointed assemblies as a theoretical advancement to prior works and provides a comparative analysis against previously established works. The study evaluates the proposed method using MATLAB to find the optimum set of actuators, and MATLAB and SAP2000 to verify the actuation results obtained through applying the set of actuations to the numerical models. The proposed method minimizes the number of trials, count of actuators, and total actuation up to 83%, 73%, and 50%, respectively. Furthermore, the optimum solution could be found in a single trial. The study focuses on the three aspects: (a) finding the optimal count of actuators; (b) optimum amount of actuation using fmincon function; and c) Implementing two-sided inequalities to control equations allowing designers to develop target internal forces and nodal displacements, as domains rather than specific numbers. This improves the optimization process affecting actuator count, total actuation elements, and processing time.

A Review of Nonlinear Control Strategies for Shape and Stress in Structural Engineering

“…Determining nodal points is the first step toward the reality of architectural forms, from the conception of design to the fulfillment of esthetic quality. This requirement is demonstrated by beams [16,29,[87][88][89][90][91][92][93][94][95], trusses [9,[96][97][98][99][100][101][102][103], and frames [104][105][106] by linear or nonlinear methods, where the exact placement of structural components guarantees the effective distribution of loads while maintaining structural integrity. In addition, the sphere [6,8,52,107,108], antenna structures [100,109,110], egg-shaped structure [4], and dome [3,5,15,111] constructions are examples of architectural achievements where geometric precision combines with esthetic appeal and practicality to create memorable areas and famous structures.…”

“…These strategies demonstrate the versatility and adaptability of concurrent shape and stress control methodologies, ranging from adaptive building facades that dynamically respond to environmental conditions [7,10,11,31,132] while managing stress to aerospace structures that optimize both aerodynamics and structural integrity [146,147]. There are some examples of combined form and stress control, such as beams, trusses [2,9,97,98,101,103,148], spheres [6,8,52], antenna structures, cable structures [30,31,103,115,116], and domes [5,111] by linear [6,8,9,52,97,98,101,148] or nonlinear [30,31] methods. The mentioned examples highlight successful implementations and offer insightful information on the efficacy and practicality of stress control techniques [2,5,6,8,9,30,31,52,97,98,101,…”

“…Traditional linear control schemes [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16], although useful, are not always able to capture the complex behaviors that are inherent in structural systems [17]. In structural engineering, nonlinearities can originate from a number of factors, including geometric configurations, material properties, large deflections or rotations, and dynamic loading scenarios [18][19][20][21].…”

Economical Aspect of Truss Design Through Geometry Configuration

“…However, the recommended value is in a wide range and the truss span is limited up to 30 m. Thus, the economical aspect on the truss configuration should be carried out for longer truss span to provide specific guidance on optimum truss design. Various research works [13][14][15][16][17][18] have been carried out on truss optimization that considered various aspects, such as constructability, natural frequency, cross-sectional minimization, sizing, shape, and topology for truss optimization. The proposed optimization method requires the industry to have deep understanding of programming language, artificial Intelligence, decision-making tools, and mathematical knowledge and may not be suitable for practicing engineer to implement the optimization method.…”

Bending Moment Control and Weight Optimization in Space Structures by Adding Extra Members in the Optimal Locations

“…The optimal design was done for I-and H-shaped crane bridge girders [36], reinforced concrete sections [37], and steel moment frames [38]. Moreover, the significance of the most active members' location to change the bars' lengths to reshape and redistribute stress in members was also studied [39][40][41][42][43]. So far, studies have not been carried out either to control bending moment in beams or to beam size optimization for space frames.…”