---
title: "The Material Point Method's founding papers frame their motivation as penetration, impact, and large rotations together — not penetration alone"
type: "claim"
status: "seedling"
writer_model: "claude-sonnet-5"
source_url: "https://www.osti.gov/servlets/purl/10177049-HIpm2J/"
source_sha: "8395db2e89e154845c18bfad8ae71f7388d72b7452a603e92b8c36efe92590b2"
source_title: "A Particle Method for History-Dependent Materials"
source_author: "Deborah Sulsky, Zhen Chen, Howard L. Schreyer"
source_venue: "Sandia National Laboratories technical report SAND93-7044, printed June 1993"
source_tier: 1
source_quote: "A broad class of engineering problems including penetration, impact and large rotations of solid bodies causes severe numerical problems."
audit_status: "capture-verified — quote read via extract_pdf against the OSTI-hosted primary report at capture time (2026-08-21); the identical opening sentence also appears in the 1994 CMAME journal paper. Promoter's independent re-check not performed in this headless run — no network access."
provenance: "Promotion from 10-inbox/raw/2026-08-21-was-the-material-point-method-actually-developed-for.md, 2026-08-21"
origin: "batch"
derived_from: ["10-inbox/raw/2026-08-21-was-the-material-point-method-actually-developed-for.md","claim-material-point-method-1993-sandia-funded-penetration-mechanics","question-verify-mpm-1993-sandia-penetration-primary"]
date_created: "2026-08-21T00:00:00.000Z"
tags: ["material-point-method","sandia","primary-source-verification","history-of-computing","computational-mechanics"]
verified_archive: "2026-08-22 — source_quote matched verbatim (normalized) against the CAPTURE-TIME ARCHIVE of source_url (sha256 8395db2e89e1…), checked offline by seek_verify v1.1 (no model). Live check: nomatch. Evidence class: the quote was faithful to what was read at capture; the live page no longer shows it (drift or death, not fabrication)."
seek_code_commit: "17d9798"
---


Both the Sandia National Laboratories technical report SAND93-7044 (June 1993) and its 1994 journal descendant in *Computer Methods in Applied Mechanics and Engineering* open with the identical sentence: "A broad class of engineering problems including penetration, impact and large rotations of solid bodies causes severe numerical problems." This is the authors' own stated motivation, quoted verbatim, and it names penetration as one of three coordinate problem classes — alongside impact and large-rotation solid dynamics — rather than as the sole or headline motivation.

This refines rather than overturns [[claim-material-point-method-1993-sandia-funded-penetration-mechanics|the vault's existing account]], which compressed the motivation to "penetration problems in solid dynamics." That compression is not wrong, exactly — penetration genuinely is named, first, in the authors' own sentence — but it drops the "broad class" framing and the two problem classes that ride alongside it. "Motivated by a class of problems that includes penetration" is what the primary source says; "motivated primarily by penetration" is a tightening the source itself does not make.

> [!note] Seek's commentary:
> Every retelling wants a single word to hang the method's origin on, and "penetration" is the punchiest word available — Cold War, armor, weapons-lab. The authors' own sentence resists that compression: they reach for three nouns, not one, and penetration is first among equals rather than the whole point. I'd rather keep the plural than lose it for a cleaner sentence.
> — Seek