Dear Barsisa Sanbato,

Your question is not correct. The matter is not in sympathy of people to use non-linear system or analysis. The matter is in describing more realistically the behavior of structure under the different loading, namely, static or dynamic. Only correct and literate approach in analysis of structures will give the best results for design of structures or for predicting of what will happen with the structure under the impact of the mentioned loads. And this approach presupposes the use of non-linear analysis. Most of the materials used in construction of buildings or other structures (ships, airplanes, dams, bridges, trains, etc.) are non-linear. As better the engineer can describe the behavior of structures using hysteresis loops (models) or other tools, as better (more realistic) results will be received. In this case your structure will be more reliable and will cost much less than a structure designed as linear system.

My field is earthquake engineering, seismic (base and roof) isolation. Many years ago, I had a task to analyze the reasons of extensive destructions of reinforced concrete frame buildings with shear walls during the disastrous Spitak Earthquake of December 7, 1988 in Armenia. This became possible only by carrying out non-linear earthquake response analysis base on the created by me hysteresis model, which is currently called as "Melkumyan Hysteresis Model". You can read about this work in my paper: Mikayel G. Melkumyan Hysteresis Model for the Shear Behavior of R/C Multistory Frame Buildings with Diaphragms under Seismic Actions (Part 1) - Principle of Formation. - "SEISAN-KENKYU" Monthly Journal of Institute of Industrial Science, University of Tokyo, 1990, Vol.42, No. 12, pp.34-37.

Hope that the above is of help and that you got to some extent the answer to your question.

Best regards,

Mikayel Melkumyan

Doctor of Sciences (Engineering), Professor

Academician of the Saint-Petersburg Arctic Academy of Sciences

Academician of the Athens Institute for Education and Research

President of the Armenian Association for Earthquake Engineering

Vice-President of the International Association of CIS Countries on Base Isolation

Member of the USA Association for Science and Technology

Foreign member of the Research Center of Seismic Resistant Structures of the Institute of Industrial Science, University of Tokyo

Eminent Expert of the Committee of Eminent Experts in International Research Base of Seismic Mitigation and Isolation of Gansu Province in China

Founder of the "Save the Yerevan Schools From Earthquakes" foundation

Director of the "Melkumyan Seismic Technologies" LLC

+374 (91) 94-54-02

[email protected]

www.melkumyanseismic.com

Dear Barsisa Sanbato, if I understand your questions correctly:

1. Only on the basis of regulatory documents. That would be legal, but not necessarily correct.

2.By choosing "crutches" you are taking responsibility for yourself.

HI everyone

The endeavor to evaluate and identify flaws within the structural designs of others is a multifaceted process that requires a confluence of theoretical knowledge, practical experience, and the application of sophisticated analytical tools. This critical evaluation process is underpinned by the principles of structural analysis, which aim to ensure that designs are not only efficient and economical but also adhere to the stringent safety standards and codes that govern the field of civil engineering.

The methodology to uncover and assess design faults involves several key steps, beginning with a thorough review of the design documentation, including calculations, drawings, and specifications. This is followed by the application of structural analysis principles to verify the accuracy of the original design's assumptions, calculations, and compliance with relevant codes and standards. Advanced computational tools, including Finite Element Analysis (FEA) software, play a pivotal role in this process, enabling engineers to simulate various load conditions and assess the structural response of different design elements.

It is important to note that the market is replete with a myriad of software tools designed for structural analysis and design, each with its unique features, capabilities, and limitations. The selection of the appropriate software is contingent upon the specific requirements of the project, including the type of structure, the materials involved, the complexity of the design, and the regulatory environment.

Regarding the licensing and regulation of software tools in the context of structural design, there is no global authoritative body that mandates the use of specific software. However, the software must be capable of designing structures in compliance with the relevant local, national, or international codes and standards. In many jurisdictions, the responsibility for ensuring the adequacy and compliance of the design, including the choice of software, falls on the licensed professional engineers or architects who are legally accountable for the integrity of their designs. These professionals are required to adhere to the ethical standards and regulations set forth by professional bodies and regulatory agencies within their jurisdictions.

In essence, the efficacy of software tools in structural design lies not in their licensure but in their ability to accurately model structural behavior under various loads and conditions, thereby ensuring designs that are both safe and compliant with the prevailing codes and standards. Continuous advancements in software technology, coupled with the rigorous training and ethical responsibilities of professional engineers, are central to the ongoing enhancement of structural design practices.

Здравствуйте, уважаемые коллеги! Ваши вопросы очень интересны. Я хотел бы разделить их на три группы. 1. Нелинейность следует использовать по существу, а не просто потому, что это модно. Есть конструкции, где нелинейность действительно необходима. Однако в целом нелинейность позволяет выявить внутренние резервы конструкции с точки зрения безопасности. 2. Все программные продукты необходимо оценивать на достоверность для различных классов задач. Результаты таких оценок должны быть доступны всем желающим.  3. Очень многое зависит от того, какую расчётную схему мы выберем для решения конкретной задачи. Это очень важный момент. Например, если мы имеем дело с нестационарными волновыми процессами, такими как ударные, взрывные или сейсмические воздействия, то необходимо чётко понимать разницу между установившимся (колебательным) и неустановившимся (волновым) характером воздействия. И в зависимости от этого выбирать соответствующую расчётную схему. Эта тема очень обширна, но сейчас настало время обсудить её более подробно.